Candesartan and Hydrochlorothiazide

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product

Tablet, Oral:

Atacand HCT: 32/25: Candesartan cilexetil 32 mg and hydrochlorothiazide 25 mg [DSC], 32/12.5: Candesartan cilexetil 32 mg and hydrochlorothiazide 12.5 mg [DSC], 16/12.5: Candesartan cilexetil 16 mg and hydrochlorothiazide 12.5 mg [DSC] [scored]

Atacand HCT: 32/25: Candesartan cilexetil 32 mg and hydrochlorothiazide 25 mg, 16/12.5: Candesartan cilexetil 16 mg and hydrochlorothiazide 12.5 mg, 32/12.5: Candesartan cilexetil 32 mg and hydrochlorothiazide 12.5 mg [scored; contains corn starch]

Generic: 16/12.5: Candesartan cilexetil 16 mg and hydrochlorothiazide 12.5 mg, 32/12.5: Candesartan cilexetil 32 mg and hydrochlorothiazide 12.5 mg, 32/25: Candesartan cilexetil 32 mg and hydrochlorothiazide 25 mg

Pharmacology

Mechanism of Action

Candesartan: Candesartan is an angiotensin receptor antagonist. Angiotensin II acts as a vasoconstrictor. In addition to causing direct vasoconstriction, angiotensin II also stimulates the release of aldosterone. Once aldosterone is released, sodium and water are reabsorbed. The end result is an elevation in blood pressure. Candesartan binds to the AT1 angiotensin II receptor. This binding prevents angiotensin II from binding to the receptor, thereby blocking the vasoconstriction and the aldosterone-secreting effects of angiotensin II.

Hydrochlorothiazide: Inhibits sodium reabsorption in the distal tubules causing increased excretion of sodium and water as well as potassium and hydrogen ions

Use: Labeled Indications

Hypertension: Management of hypertension (not for initial therapy)

Contraindications

Hypersensitivity to candesartan, hydrochlorothiazide or other sulfonamide-derived drugs, or any component of the formulation; anuria; concomitant use with aliskiren in patients with diabetes mellitus

Note: Although the FDA approved product labeling states this medication is contraindicated with other sulfonamide-containing drug classes, the scientific basis of this statement has been challenged. See “Warnings/Precautions” for more detail.

Canadian labeling: Additional contraindications (not in US labeling): Concomitant use with aliskiren in patients with moderate to severe renal impairment (GFR <60 mL/minute/1.73 m²); severe renal impairment (CrCl <30 mL/minute/1.73 m²); severe hepatic impairment and/or cholestasis; gout; hereditary problems of galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption; pregnancy; breast-feeding; infants <1 year of age

Dosage and Administration

Dosing: Adult

Hypertension, replacement therapy: Oral: Combination product can be substituted for individual agents; maximum therapeutic effect would be expected within 4 weeks

Usual dosage range:

Candesartan: 8 to 32 mg daily, given once daily or twice daily in divided doses

Hydrochlorothiazide: 12.5 to 50 mg once daily

Dosing: Geriatric

No initial dosage adjustment is recommended. Refer to adult dosing.

Administration

May administer with or without food.

Storage

Store at 25°C (77°F). Store in tightly closed container.

Drug Interactions

Ajmaline: Sulfonamides may enhance the adverse/toxic effect of Ajmaline. Specifically, the risk for cholestasis may be increased. Monitor therapy

Alcohol (Ethyl): May enhance the orthostatic hypotensive effect of Thiazide and Thiazide-Like Diuretics. Monitor therapy

Alfuzosin: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Aliskiren: May enhance the hyperkalemic effect of Angiotensin II Receptor Blockers. Aliskiren may enhance the hypotensive effect of Angiotensin II Receptor Blockers. Aliskiren may enhance the nephrotoxic effect of Angiotensin II Receptor Blockers. Management: Aliskiren use with ACEIs or ARBs in patients with diabetes is contraindicated. Combined use in other patients should be avoided, particularly when CrCl is less than 60 mL/min. If combined, monitor potassium, creatinine, and blood pressure closely. Consider therapy modification

Allopurinol: Thiazide and Thiazide-Like Diuretics may enhance the potential for allergic or hypersensitivity reactions to Allopurinol. Thiazide and Thiazide-Like Diuretics may increase the serum concentration of Allopurinol. Specifically, Thiazide Diuretics may increase the concentration of Oxypurinol, an active metabolite of Allopurinol. Monitor therapy

Amifostine: Blood Pressure Lowering Agents may enhance the hypotensive effect of Amifostine. Management: When amifostine is used at chemotherapy doses, blood pressure lowering medications should be withheld for 24 hours prior to amifostine administration. If blood pressure lowering therapy cannot be withheld, amifostine should not be administered. Consider therapy modification

Aminolevulinic Acid (Systemic): Photosensitizing Agents may enhance the photosensitizing effect of Aminolevulinic Acid (Systemic). Avoid combination

Aminolevulinic Acid (Topical): Photosensitizing Agents may enhance the photosensitizing effect of Aminolevulinic Acid (Topical). Monitor therapy

Amphetamines: May diminish the antihypertensive effect of Antihypertensive Agents. Monitor therapy

Angiotensin II: Receptor Blockers may diminish the therapeutic effect of Angiotensin II. Monitor therapy

Angiotensin-Converting Enzyme Inhibitors: Angiotensin II Receptor Blockers may enhance the adverse/toxic effect of Angiotensin-Converting Enzyme Inhibitors. Angiotensin II Receptor Blockers may increase the serum concentration of Angiotensin-Converting Enzyme Inhibitors. Management: In US labeling, use of telmisartan and ramipril is not recommended. It is not clear if any other combination of an ACE inhibitor and an ARB would be any safer. Consider alternatives to the combination when possible. Consider therapy modification

Anticholinergic Agents: May increase the serum concentration of Thiazide and Thiazide-Like Diuretics. Monitor therapy

Antidiabetic Agents: Thiazide and Thiazide-Like Diuretics may diminish the therapeutic effect of Antidiabetic Agents. Monitor therapy

Antidiabetic Agents: Hyperglycemia-Associated Agents may diminish the therapeutic effect of Antidiabetic Agents. Monitor therapy

Antihepaciviral Combination Products: May increase the serum concentration of Candesartan. Management: Per antihepaciviral combination product US prescribing information, consider decreasing the candesartan dose and monitoring for evidence of hypotension and worsening renal function if these agents are used in combination. Consider therapy modification

Antipsychotic Agents (Second Generation [Atypical]): Blood Pressure Lowering Agents may enhance the hypotensive effect of Antipsychotic Agents (Second Generation [Atypical]). Monitor therapy

Barbiturates: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Benperidol: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Beta2-Agonists: May enhance the hypokalemic effect of Thiazide and Thiazide-Like Diuretics. Monitor therapy

Bile Acid Sequestrants: May decrease the absorption of Thiazide and Thiazide-Like Diuretics. The diuretic response is likewise decreased. Consider therapy modification

Brigatinib: May diminish the antihypertensive effect of Antihypertensive Agents. Brigatinib may enhance the bradycardic effect of Antihypertensive Agents. Monitor therapy

Brimonidine (Topical): May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Bromperidol: Blood Pressure Lowering Agents may enhance the hypotensive effect of Bromperidol. Bromperidol may diminish the hypotensive effect of Blood Pressure Lowering Agents. Avoid combination

Calcium Salts: Thiazide and Thiazide-Like Diuretics may decrease the excretion of Calcium Salts. Continued concomitant use can also result in metabolic alkalosis. Monitor therapy

CarBAMazepine: Thiazide and Thiazide-Like Diuretics may enhance the adverse/toxic effect of CarBAMazepine. Specifically, there may be an increased risk for hyponatremia. Monitor therapy

Cardiac Glycosides: Thiazide and Thiazide-Like Diuretics may enhance the adverse/toxic effect of Cardiac Glycosides. Specifically, cardiac glycoside toxicity may be enhanced by the hypokalemic and hypomagnesemic effect of thiazide diuretics. Monitor therapy

Corticosteroids (Orally Inhaled): May enhance the hypokalemic effect of Thiazide and Thiazide-Like Diuretics. Monitor therapy

Corticosteroids (Systemic): May enhance the hypokalemic effect of Thiazide and Thiazide-Like Diuretics. Monitor therapy

Cyclophosphamide: Thiazide and Thiazide-Like Diuretics may enhance the adverse/toxic effect of Cyclophosphamide. Specifically, granulocytopenia may be enhanced. Monitor therapy

CycloSPORINE (Systemic): Angiotensin II Receptor Blockers may enhance the hyperkalemic effect of CycloSPORINE (Systemic). Monitor therapy

Dapoxetine: May enhance the orthostatic hypotensive effect of Angiotensin II Receptor Blockers. Monitor therapy

Dexketoprofen: May enhance the adverse/toxic effect of Sulfonamides. Monitor therapy

Dexmethylphenidate: May diminish the therapeutic effect of Antihypertensive Agents. Monitor therapy

Diacerein: May enhance the therapeutic effect of Diuretics. Specifically, the risk for dehydration or hypokalemia may be increased. Monitor therapy

Diazoxide: Thiazide and Thiazide-Like Diuretics may enhance the adverse/toxic effect of Diazoxide. Monitor therapy

Diazoxide: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Dichlorphenamide: Thiazide and Thiazide-Like Diuretics may enhance the hypokalemic effect of Dichlorphenamide. Monitor therapy

Dofetilide: HydroCHLOROthiazide may enhance the QTc-prolonging effect of Dofetilide. HydroCHLOROthiazide may increase the serum concentration of Dofetilide. Avoid combination

Drospirenone: Angiotensin II Receptor Blockers may enhance the hyperkalemic effect of Drospirenone. Monitor therapy

DULoxetine: Blood Pressure Lowering Agents may enhance the hypotensive effect of DULoxetine. Monitor therapy

Eplerenone: May enhance the hyperkalemic effect of Angiotensin II Receptor Blockers. Monitor therapy

Fexinidazole [INT]: Thiazide and Thiazide-Like Diuretics may enhance the arrhythmogenic effect of Fexinidazole [INT]. Avoid combination

Heparin: May enhance the hyperkalemic effect of Angiotensin II Receptor Blockers. Monitor therapy

Heparins (Low Molecular Weight): May enhance the hyperkalemic effect of Angiotensin II Receptor Blockers. Monitor therapy

Herbs (Hypertensive Properties): May diminish the antihypertensive effect of Antihypertensive Agents. Monitor therapy

Herbs (Hypotensive Properties): May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Hypotension-Associated Agents: Blood Pressure Lowering Agents may enhance the hypotensive effect of Hypotension-Associated Agents. Monitor therapy

Ipragliflozin: May enhance the adverse/toxic effect of Thiazide and Thiazide-Like Diuretics. Specifically, the risk for intravascular volume depletion may be increased. Monitor therapy

Ivabradine: Thiazide and Thiazide-Like Diuretics may enhance the arrhythmogenic effect of Ivabradine. Monitor therapy

Levodopa-Containing Products: Blood Pressure Lowering Agents may enhance the hypotensive effect of Levodopa-Containing Products. Monitor therapy

Levosulpiride: Thiazide and Thiazide-Like Diuretics may enhance the adverse/toxic effect of Levosulpiride. Avoid combination

Licorice: May enhance the hypokalemic effect of Thiazide and Thiazide-Like Diuretics. Monitor therapy

Lithium: Thiazide and Thiazide-Like Diuretics may decrease the excretion of Lithium. Consider therapy modification

Lithium: Angiotensin II Receptor Blockers may increase the serum concentration of Lithium. Management: Lithium dosage reductions will likely be needed following the addition of an angiotensin II receptor antagonist. Consider therapy modification

Lormetazepam: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Mecamylamine: Sulfonamides may enhance the adverse/toxic effect of Mecamylamine. Avoid combination

Methenamine: Thiazide and Thiazide-Like Diuretics may diminish the therapeutic effect of Methenamine. Monitor therapy

Methylphenidate: May diminish the antihypertensive effect of Antihypertensive Agents. Monitor therapy

Molsidomine: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Multivitamins/Fluoride (with ADE): May enhance the hypercalcemic effect of Thiazide and Thiazide-Like Diuretics. Monitor therapy

Multivitamins/Minerals (with ADEK, Folate, Iron): Thiazide and Thiazide-Like Diuretics may enhance the hypercalcemic effect of Multivitamins/Minerals (with ADEK, Folate, Iron). Monitor therapy

Multivitamins/Minerals (with AE, No Iron): Thiazide and Thiazide-Like Diuretics may increase the serum concentration of Multivitamins/Minerals (with AE, No Iron). Specifically, thiazide diuretics may decrease the excretion of calcium, and continued concomitant use can also result in metabolic alkalosis. Monitor therapy

Naftopidil: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Neuromuscular-Blocking Agents (Nondepolarizing): Thiazide and Thiazide-Like Diuretics may enhance the neuromuscular-blocking effect of Neuromuscular-Blocking Agents (Nondepolarizing). Monitor therapy

Nicergoline: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Nicorandil: May enhance the hyperkalemic effect of Angiotensin II Receptor Blockers. Monitor therapy

Nicorandil: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Nitroprusside: Blood Pressure Lowering Agents may enhance the hypotensive effect of Nitroprusside. Monitor therapy

Nonsteroidal Anti-Inflammatory Agents: Thiazide and Thiazide-Like Diuretics may enhance the nephrotoxic effect of Nonsteroidal Anti-Inflammatory Agents. Nonsteroidal Anti-Inflammatory Agents may diminish the therapeutic effect of Thiazide and Thiazide-Like Diuretics. Monitor therapy

Nonsteroidal Anti-Inflammatory Agents: Angiotensin II Receptor Blockers may enhance the adverse/toxic effect of Nonsteroidal Anti-Inflammatory Agents. Specifically, the combination may result in a significant decrease in renal function. Nonsteroidal Anti-Inflammatory Agents may diminish the therapeutic effect of Angiotensin II Receptor Blockers. The combination of these two agents may also significantly decrease glomerular filtration and renal function. Monitor therapy

Obinutuzumab: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Management: Consider temporarily withholding blood pressure lowering medications beginning 12 hours prior to obinutuzumab infusion and continuing until 1 hour after the end of the infusion. Consider therapy modification

Opioid Agonists: May enhance the adverse/toxic effect of Diuretics. Opioid Agonists may diminish the therapeutic effect of Diuretics. Monitor therapy

OXcarbazepine: Thiazide and Thiazide-Like Diuretics may enhance the adverse/toxic effect of OXcarbazepine. Specifically, there may be an increased risk for hyponatremia. Monitor therapy

Pentoxifylline: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Pholcodine: Blood Pressure Lowering Agents may enhance the hypotensive effect of Pholcodine. Monitor therapy

Phosphodiesterase 5 Inhibitors: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Porfimer: Photosensitizing Agents may enhance the photosensitizing effect of Porfimer. Monitor therapy

Potassium Salts: May enhance the hyperkalemic effect of Angiotensin II Receptor Blockers. Monitor therapy

Potassium-Sparing Diuretics: Angiotensin II Receptor Blockers may enhance the hyperkalemic effect of Potassium-Sparing Diuretics. Monitor therapy

Promazine: Thiazide and Thiazide-Like Diuretics may enhance the QTc-prolonging effect of Promazine. Avoid combination

Prostacyclin Analogues: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Quinagolide: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy

Ranolazine: May enhance the adverse/toxic effect of Angiotensin II Receptor Blockers. Monitor therapy

Reboxetine: May enhance the hypokalemic effect of Thiazide and Thiazide-Like Diuretics. Monitor therapy

Selective Serotonin Reuptake Inhibitors: May enhance the hyponatremic effect of Thiazide and Thiazide-Like Diuretics. Monitor therapy

Sodium Phosphates: Angiotensin II Receptor Blockers may enhance the nephrotoxic effect of Sodium Phosphates. Specifically, the risk of acute phosphate nephropathy may be enhanced. Management: Consider avoiding this combination by temporarily suspending treatment with ARBs, or seeking alternatives to oral sodium phosphate bowel preparation. If the combination cannot be avoided, maintain adequate hydration and monitor renal function closely. Consider therapy modification

Sodium Phosphates: Diuretics may enhance the nephrotoxic effect of Sodium Phosphates. Specifically, the risk of acute phosphate nephropathy may be enhanced. Management: Consider avoiding this combination by temporarily suspending treatment with diuretics, or seeking alternatives to oral sodium phosphate bowel preparation. If the combination cannot be avoided, hydrate adequately and monitor fluid and renal status. Consider therapy modification

Tacrolimus (Systemic): Angiotensin II Receptor Blockers may enhance the hyperkalemic effect of Tacrolimus (Systemic). Monitor therapy

Tolvaptan: May enhance the hyperkalemic effect of Angiotensin II Receptor Blockers. Monitor therapy

Topiramate: Thiazide and Thiazide-Like Diuretics may enhance the hypokalemic effect of Topiramate. Thiazide and Thiazide-Like Diuretics may increase the serum concentration of Topiramate. Management: Monitor for increased topiramate levels/adverse effects (e.g., hypokalemia) with initiation/dose increase of a thiazide diuretic. Closely monitor serum potassium concentrations with concomitant therapy. Topiramate dose reductions may be necessary. Consider therapy modification

Toremifene: Thiazide and Thiazide-Like Diuretics may enhance the hypercalcemic effect of Toremifene. Monitor therapy

Trimethoprim: May enhance the hyperkalemic effect of Angiotensin II Receptor Blockers. Monitor therapy

Valsartan: HydroCHLOROthiazide may enhance the hypotensive effect of Valsartan. Valsartan may increase the serum concentration of HydroCHLOROthiazide. Monitor therapy

Verteporfin: Photosensitizing Agents may enhance the photosensitizing effect of Verteporfin. Monitor therapy

Vitamin D Analogs: Thiazide and Thiazide-Like Diuretics may enhance the hypercalcemic effect of Vitamin D Analogs. Monitor therapy

Yohimbine: May diminish the antihypertensive effect of Antihypertensive Agents. Monitor therapy

Test Interactions

See individual agents.

Adverse Reactions

Reactions which follow have been reported with the combination product; see individual drug agents for additional adverse reactions that may be expected from each agent.

1% to 10%:

Central nervous system: Dizziness (3%), headache (3%, placebo 5%)

Neuromuscular & skeletal: Back pain (3%)

Respiratory: Upper respiratory tract infection (4%), flu-like symptoms (3%)

<1%: Abdominal pain, agranulocytosis, angina pectoris, angioedema (<0.5%), anxiety, arthralgia, arthritis, bradycardia, bronchitis, chest pain, conjunctivitis, cough, cystitis, depression, dermatitis, diaphoresis, diarrhea, dyspepsia, dyspnea, ECG abnormality, eczema, epistaxis, extrasystoles, fatigue, gastritis, gastroenteritis, hematuria, hepatic abnormality, hepatitis, hyperglycemia, hyperuricemia, hypoesthesia, hypokalemia, increased blood urea nitrogen, increased creatine phosphokinase, increased serum transaminases, increased susceptibility to infection, insomnia, leg cramps, leukopenia, myalgia, myocardial infarction (<0.5%), nausea, neutropenia, osteoarthritis, pain, palpitations, paresthesia, peripheral edema, pharyngitis, pruritus, rash, rhinitis, sciatica, sinusitis, tachycardia, tinnitus, urinary tract infection, urticaria, vertigo, viral infection, vomiting, weakness

Warnings/Precautions

Concerns related to adverse effects:

• Angioedema: Angioedema has been reported rarely with some angiotensin II receptor antagonists (ARBs) and may occur at any time during treatment (especially following first dose). It may involve the head and neck (potentially compromising airway) or the intestine (presenting with abdominal pain). Patients with idiopathic or hereditary angioedema or previous angioedema associated with angiotensin-converting enzyme (ACE) inhibitor therapy may be at an increased risk. Prolonged frequent monitoring may be required, especially if tongue, glottis, or larynx are involved, as they are associated with airway obstruction. Patients with a history of airway surgery may have a higher risk of airway obstruction. Discontinue therapy immediately if angioedema occurs. Aggressive early management is critical. Intramuscular (IM) administration of epinephrine may be necessary. Do not readminister to patients who have had angioedema with ARBs.
• Electrolyte disturbances: Hyperkalemia may occur with angiotensin II receptor antagonists; risk factors include renal dysfunction, diabetes mellitus, and concomitant use of potassium-sparing diuretics, potassium supplements, and/or potassium-containing salts. Use cautiously, if at all, with these agents and monitor potassium closely. Thiazide diuretics may cause hypokalemia, hypochloremic alkalosis, hypomagnesemia, and hyponatremia.
• Gout: In certain patients with a history of gout, a familial predisposition to gout, or chronic renal failure, gout can be precipitated by hydrochlorothiazide. This risk may be increased with doses ≥25 mg (Gurwitz 1997). The Canadian labeling contraindicates use in patients with gout.
• Hypersensitivity reactions: Hypersensitivity reactions may occur with hydrochlorothiazide. Risk is increased in patients with a history of allergy or bronchial asthma.
• Hypotension: Symptomatic hypotension may occur upon initiation in patients who are salt or volume depleted (eg, those treated with high-dose diuretics); correct volume depletion prior to administration. This transient hypotensive response is not a contraindication to further treatment with candesartan/hydrochlorothiazide. Advise patients to avoid ethanol; may potentiate orthostatic hypotension.
• Ocular effects: Hydrochlorothiazide may cause acute transient myopia and acute angle-closure glaucoma, typically occurring within hours to weeks following initiation; discontinue therapy immediately in patients with acute decreases in visual acuity or ocular pain. Additional treatments may be needed if uncontrolled intraocular pressure persists. Risk factors may include a history of sulfonamide or penicillin allergy.
• Photosensitivity: Photosensitization may occur.
• Renal function deterioration: May be associated with deterioration of renal function and/or increases in serum creatinine, particularly in patients with low renal blood flow (eg, renal artery stenosis, heart failure) whose glomerular filtration rate (GFR) is dependent on efferent arteriolar vasoconstriction by angiotensin II; deterioration may result in oliguria, acute renal failure, and progressive azotemia. Small increases in serum creatinine may occur following initiation; consider discontinuation only in patients with progressive and/or significant deterioration in renal function.
• Sulfonamide (“sulfa”) allergy: The FDA-approved product labeling for many medications containing a sulfonamide chemical group includes a broad contraindication in patients with a prior allergic reaction to sulfonamides. There is a potential for cross-reactivity between members of a specific class (eg, two antibiotic sulfonamides). However, concerns for cross-reactivity have previously extended to all compounds containing the sulfonamide structure (SO₂NH₂). An expanded understanding of allergic mechanisms indicates cross-reactivity between antibiotic sulfonamides and nonantibiotic sulfonamides may not occur or at the very least this potential is extremely low (Brackett 2004; Johnson 2005; Slatore 2004; Tornero 2004). In particular, mechanisms of cross-reaction due to antibody production (anaphylaxis) are unlikely to occur with nonantibiotic sulfonamides. T-cell-mediated (type IV) reactions (eg, maculopapular rash) are less well understood and it is not possible to completely exclude this potential based on current insights. In cases where prior reactions were severe (Stevens-Johnson syndrome/TEN), some clinicians choose to avoid exposure to these classes.

Disease-related concerns:

• Aortic/mitral stenosis: Use with caution in patients with significant aortic/mitral stenosis.
• Bariatric surgery: Dehydration: Avoid diuretics in the immediate postoperative period after bariatric surgery; electrolyte disturbances and dehydration may occur. Diuretics may be resumed, if indicated, once oral fluid intake goals are met (Ziegler 2009).
• Diabetes: Use hydrochlorothiazide with caution in patients with prediabetes or diabetes mellitus; may see a change in glucose control.
• Hepatic impairment: Systemic exposure of candesartan is increased in hepatic impairment. Not recommended for initiation in patients with moderate to severe hepatic impairment. In progressive or severe liver disease, avoid electrolyte and acid/base imbalances that might lead to hepatic encephalopathy/coma. The Canadian labeling contraindicates use in severe impairment or cholestasis.
• Hypercalcemia: Thiazide diuretics may decrease renal calcium excretion; consider avoiding use in patients with hypercalcemia.
• Hypercholesterolemia: Use with caution in patients with moderate or high cholesterol concentrations; increased cholesterol and triglyceride levels have been reported with thiazides.
• Parathyroid disease: Thiazide diuretics reduce calcium excretion; pathologic changes in the parathyroid glands with hypercalcemia and hypophosphatemia have been observed with prolonged use; should be discontinued prior to testing for parathyroid function.
• Renal artery stenosis: Use candesartan with caution in patients with unstented unilateral/bilateral renal artery stenosis. When unstented bilateral renal artery stenosis is present, use is generally avoided due to the elevated risk of deterioration in renal function unless possible benefits outweigh risks.
• Renal impairment: Use candesartan with caution in patients with preexisting renal insufficiency. Cumulative effects may develop, including azotemia, in patients with impaired renal function. Avoid hydrochlorothiazide in severe renal disease (ineffective). Use is contraindicated in anuric patients. The Canadian labeling also contraindicates use in patients with severe renal impairment (CrCl <30 mL/minute/1.73 m²).
• Systemic lupus erythematosus (SLE): Hydrochlorothiazide can cause SLE exacerbation or activation.

Concurrent drug therapy issues:

• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Special populations:

• Pregnancy: [US Boxed Warning]: Drugs that act on the renin-angiotensin system can cause injury and death to the developing fetus. Discontinue as soon as possible once pregnancy is detected.
• Surgical patients: In patients on chronic angiotensin receptor blocker (ARB) therapy, intraoperative hypotension may occur with induction and maintenance of general anesthesia; however, discontinuation of therapy prior to surgery is controversial. If continued preoperatively, avoidance of hypotensive agents during surgery is prudent (Hillis, 2011).

Monitoring Parameters

Blood pressure, heart rate; serum electrolytes (eg, sodium, potassium); BUN, creatinine

Pregnancy

Pregnancy Risk Factor

D

Pregnancy Considerations

[US Boxed Warning]: Drugs that act on the renin-angiotensin system can cause injury and death to the developing fetus. Discontinue as soon as possible once pregnancy is detected. Also see individual agents for additional information.

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)
• Have patient report immediately to prescriber signs of high blood sugar (confusion, fatigue, increased thirst, increased hunger, passing a lot of urine, flushing, fast breathing, or breath that smells like fruit), signs of fluid and electrolyte problems (mood changes, confusion, muscle pain or weakness, abnormal heartbeat, severe dizziness, passing out, fast heartbeat, increased thirst, seizures, loss of strength and energy, lack of appetite, unable to pass urine or change in amount of urine passed, dry mouth, dry eyes, nausea, or vomiting), signs of kidney problems (unable to pass urine, blood in the urine, change in amount of urine passed, or weight gain), signs of lupus (rash on the cheeks or other body parts, sunburn easy, muscle or joint pain, chest pain or shortness of breath, or swelling in the arms or legs), skin changes, vision changes, or eye pain (HCAHPS).
• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.