Dosage Forms
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Cream, Rectal:
Preparation H: Phenylephrine hydrochloride 0.25%, pramoxine hydrochloride 1%, glycerin 14.4%, and white petrolatum 15% (26 g, 51 g) [contains cetyl alcohol, edetate disodium, methylparaben, propylene glycol, propylparaben, sodium benzoate]
Preparation H Totables: Phenylephrine hydrochloride 0.25%, pramoxine hydrochloride 1%, glycerin 14.4%, and white petrolatum 15% (5.7 g [DSC]) [contains cetyl alcohol, edetate disodium, methylparaben, propylene glycol, propylparaben, sodium benzoate]
Pharmacology
Mechanism of Action
Phenylephrine: Potent, direct-acting alpha-adrenergic agonist with virtually no beta-adrenergic activity; produces local vasoconstriction.
Pramoxine: Like other anesthetics, it decreases the neuronal membrane's permeability to sodium ions; both initiation and conduction of nerve impulses are blocked, thus depolarization of the neuron is inhibited.
Use: Labeled Indications
Hemorrhoids: Temporary relief of pain, soreness, burning, local itching, and discomfort associated with hemorrhoids.
Dosage and Administration
Dosing: Adult
Hemorrhoids: Rectal: Apply externally to affected area up to 4 times daily.
Dosing: Geriatric
Refer to adult dosing.
Dosing: Pediatric
Hemorrhoids: Children ≥12 years: Refer to adult dosing.
Administration
Cleanse affected area by patting or blotting with cleansing wipe, and gently dry before applying cream. Apply externally or in the lower portion of the anal canal only. For application in the lower anal canal, remove cover from dispensing cap and attach dispensing cap to tube; lubricate dispensing cap well, then gently insert dispensing cap partway into the anus. Thoroughly cleanse dispensing cap after each use and replace cover.
Storage
Store at 20°C to 25°C (68°F to 77°F).
Drug Interactions
Alpha1-Blockers: May diminish the vasoconstricting effect of Alpha1-Agonists. Similarly, Alpha1-Agonists may antagonize Alpha1-Blocker vasodilation. Monitor therapy
AtoMOXetine: May enhance the hypertensive effect of Sympathomimetics. AtoMOXetine may enhance the tachycardic effect of Sympathomimetics. Monitor therapy
Cannabinoid-Containing Products: May enhance the tachycardic effect of Sympathomimetics. Exceptions: Cannabidiol. Monitor therapy
Cocaine (Topical): May enhance the hypertensive effect of Sympathomimetics. Management: Consider alternatives to use of this combination when possible. Monitor closely for substantially increased blood pressure or heart rate and for any evidence of myocardial ischemia with concurrent use. Consider therapy modification
Doxofylline: Sympathomimetics may enhance the adverse/toxic effect of Doxofylline. Monitor therapy
Ergot Derivatives: May enhance the hypertensive effect of Alpha1-Agonists. Ergot Derivatives may enhance the vasoconstricting effect of Alpha1-Agonists. Exceptions: Ergoloid Mesylates; Nicergoline. Avoid combination
Guanethidine: May enhance the arrhythmogenic effect of Sympathomimetics. Guanethidine may enhance the hypertensive effect of Sympathomimetics. Monitor therapy
Iobenguane Radiopharmaceutical Products: Alpha1-Agonists may diminish the therapeutic effect of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer these drugs until at least 7 days after each iobenguane dose. Avoid combination
Linezolid: May enhance the hypertensive effect of Sympathomimetics. Management: Reduce initial doses of sympathomimetic agents, and closely monitor for enhanced pressor response, in patients receiving linezolid. Specific dose adjustment recommendations are not presently available. Consider therapy modification
Methemoglobinemia Associated Agents: May enhance the adverse/toxic effect of Local Anesthetics. Specifically, the risk for methemoglobinemia may be increased. Monitor therapy
Monoamine Oxidase Inhibitors: May enhance the hypertensive effect of Alpha1-Agonists. While linezolid is expected to interact via this mechanism, management recommendations differ from other monoamine oxidase inhibitors. Refer to linezolid specific monographs for details. Exceptions: Linezolid. Avoid combination
Solriamfetol: Sympathomimetics may enhance the hypertensive effect of Solriamfetol. Monitor therapy
Sympathomimetics: May enhance the adverse/toxic effect of other Sympathomimetics. Monitor therapy
Tedizolid: May enhance the hypertensive effect of Sympathomimetics. Tedizolid may enhance the tachycardic effect of Sympathomimetics. Monitor therapy
Tricyclic Antidepressants: May enhance the therapeutic effect of Alpha1-Agonists. Tricyclic Antidepressants may diminish the therapeutic effect of Alpha1-Agonists. Monitor therapy
Adverse Reactions
See individual agents. There are no adverse reactions listed in the manufacturer’s labeling.
Warnings/Precautions
Disease-related concerns:
- Cardiovascular disease, including ischemic heart disease: Use caution.
- Diabetes mellitus: Use caution.
- Hyperthyroidism: Use caution.
- Intraocular pressure (increased): Use caution.
- Prostatic hyperplasia: Use caution.
Special populations:
- Elderly: Use caution.
Other warnings/precautions:
- Self-medication (OTC use): For external use only. When used for self-medication, notify healthcare provider if condition worsens or does not improve within 7 days or if bleeding occurs; clears up and occurs again within a few days; or if accompanied by additional symptoms (eg, swelling, rash, irritation).
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 rectal bleeding, rectal pain, or severe rectal irritation (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.
