6 Interactions found for:
Drug Interactions
Moderate
Zyrtec
+ Tizanidine
The following applies to the ingredients: Cetirizine (found in Zyrtec) and Tizanidine
MONITOR: The sedative effect of tizanidine may be potentiated by concomitant use of other agents with central nervous system (CNS) depressant effects. In addition, tizanidine and many of these agents (e.g., alcohol, anxiolytics, sedatives, hypnotics, antidepressants, antipsychotics, opioids, muscle relaxants) also can exhibit hypotensive effects, which may be additive during coadministration and may increase the risk of symptomatic hypotension and orthostasis, particularly during initiation of therapy or dose escalation. Tizanidine itself is a central alpha-2 adrenergic agonist. Pharmacologic studies have found tizanidine to possess between 1/10 to 1/50 of the potency of clonidine, a structurally similar agent, in lowering blood pressure. In a single-dose study where blood pressure was monitored closely after dosing, two-thirds of patients treated with an 8 mg dose had a 20% reduction in either the diastolic or systolic blood pressure. The reduction was seen within 1 hour after dosing, peaked 2 to 3 hours after dosing, and was associated at times with bradycardia, orthostatic hypotension, lightheadedness, dizziness, and rarely, syncope. The hypotensive effect of tizanidine is dose-related and has been measured following single doses of 2 mg or more.
MANAGEMENT: Caution is advised and more gradual dose titration may be appropriate when tizanidine is used with other substances that can cause CNS depression and/or hypotension, particularly in elderly or debilitated patients. Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to avoid rising abruptly from a sitting or recumbent position. Patients should contact their physician if they experience dizziness, lightheadedness, syncope, orthostasis, or excessive CNS effects that interfere with their normal activities.
References
- "Product Information. Zanaflex (tizanidine)." Acorda Therapeutics PROD (2001):
Drug and Food Interactions
Moderate
Zyrtec
+ Food
The following applies to the ingredients: Cetirizine (found in Zyrtec)
GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of CNS-active agents. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.
MANAGEMENT: Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol. Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.
References
- Warrington SJ, Ankier SI, Turner P "Evaluation of possible interactions between ethanol and trazodone or amitriptyline." Neuropsychobiology 15 (1986): 31-7
- Gilman AG, eds., Nies AS, Rall TW, Taylor P "Goodman and Gilman's the Pharmacological Basis of Therapeutics." New York, NY: Pergamon Press Inc. (1990):
- "Product Information. Fycompa (perampanel)." Eisai Inc (2012):
- "Product Information. Rexulti (brexpiprazole)." Otsuka American Pharmaceuticals Inc (2015):
Drug and Pregnancy Interactions
Minor
Zyrtec
+ Pregnancy
The following applies to the ingredients: Cetirizine (found in Zyrtec)
This drug should not be used during pregnancy unless the benefit outweighs the risk to the fetus.
AU TGA pregnancy category: B2
US FDA pregnancy category: Not formally assigned to a pregnancy category.
Animal models have failed to reveal evidence of teratogenicity and harmful effects on pregnancy, embryofetal development, parturition, and/or postnatal development. There are no controlled data in human pregnancy.
AU TGA pregnancy category B2: Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed. Studies in animals are inadequate or may be lacking, but available data show no evidence of an increased occurrence of fetal damage.
US FDA pregnancy category Not Assigned: The US FDA has amended the pregnancy labeling rule for prescription drug products to require labeling that includes a summary of risk, a discussion of the data supporting that summary, and relevant information to help health care providers make prescribing decisions and counsel women about the use of drugs during pregnancy. Pregnancy categories A, B, C, D, and X are being phased out.
References
- "Product Information. Zyrtec (cetirizine)." Pfizer U.S. Pharmaceuticals PROD (2001):
- Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
- Cerner Multum, Inc. "Australian Product Information." O 0
Minor
Tizanidine
+ Pregnancy
The following applies to the ingredients: Tizanidine
Benefit should outweigh risk
US FDA pregnancy category: C
Teratogenicity was not shown in animal studies in rats and rabbits. At doses up to 8 times the maximum recommended human dose, increased gestation duration was observed in rats. Pre and prenatal and postnatal pup loss and developmental retardation occurred in rats and rabbits and post-implantation loss was increased in rabbits at doses of 1 mg/kg or more. There are no controlled studies in pregnant women.
US FDA pregnancy category C: Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.
References
- "Product Information. Zanaflex (tizanidine)." Acorda Therapeutics PROD (2001):
Drug and Breastfeeding Interactions
Major
Zyrtec
+ Breastfeeding
The following applies to the ingredients: Cetirizine (found in Zyrtec)
Use with caution.
-Some experts recommend: Use is not recommended.
Excreted into human milk: Yes
Drug concentrations in breastmilk were approximately 25% to 90% of drug concentrations in plasma.
References
- "Product Information. Zyrtec (cetirizine)." Pfizer U.S. Pharmaceuticals PROD (2001):
- Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
- Cerner Multum, Inc. "Australian Product Information." O 0
- United States National Library of Medicine "Toxnet. Toxicology Data Network. http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT" (2013):
- Department of Adolescent and Child Health and Development. UNICEF. World Health Organization "Breastfeeding and maternal medication: recommendations for drugs in the eleventh Who model list of essential drugs. http://whqlibdoc.who.int/hq/2002/55732.pdf?ua=1" (2014):
Major
Tizanidine
+ Breastfeeding
The following applies to the ingredients: Tizanidine
Safety has not been established
Excreted into human milk: Unknown
Excreted into animal milk: Yes
Comments: If used, monitor infant for toxicity such as sedation, hypotension, and hallucinations.
As a lipid soluble drug, it might be expected to pass into breast milk.
References
- "Product Information. Zanaflex (tizanidine)." Acorda Therapeutics PROD (2001):
- Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
Therapeutic Duplication Warnings
No warnings were found for your selected drugs.Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.
Switch to: Consumer Interactions
| Drug Interaction Classification | |
|---|---|
These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication. |
|
| Major | Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. |
| Moderate | Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. |
| Minor | Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. |
| Unknown | No interaction information available. |
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