Drug Interactions between maraviroc and Phenergan VC
This report displays the potential drug interactions for the following 2 drugs:
- maraviroc
- Phenergan VC (phenylephrine/promethazine)
Interactions between your drugs
promethazine maraviroc
Applies to: Phenergan VC (phenylephrine / promethazine) and maraviroc
MONITOR: Maraviroc may potentiate the hypotensive effect of some medications. In clinical trials, symptomatic postural hypotension was observed more often with maraviroc than with placebo when administered to healthy volunteers at higher than recommended dosages. However, when given at the recommended dosage to HIV subjects, postural hypotension occurred at a rate similar to placebo (approximately 0.5%).
MANAGEMENT: Caution is advised when maraviroc is prescribed to patients on concomitant medications known to lower blood pressure. Close monitoring for development of hypotension is recommended. Ambulatory patients should be advised to avoid rising abruptly from a sitting or recumbent position and to notify their doctor if they experience dizziness, lightheadedness, syncope, orthostasis, or tachycardia.
References
- (2007) "Product Information. Selzentry (maraviroc)." Pfizer U.S. Pharmaceuticals Group
Drug and food interactions
promethazine food
Applies to: Phenergan VC (phenylephrine / promethazine)
GENERALLY AVOID: Concurrent use of ethanol and phenothiazines may result in additive CNS depression and psychomotor impairment. Also, ethanol may precipitate dystonic reactions in patients who are taking phenothiazines. The two drugs probably act on different sites in the brain, although the exact mechanism of the interaction is not known.
MANAGEMENT: Patients should be advised to avoid alcohol during phenothiazine therapy.
References
- Lutz EG (1976) "Neuroleptic-induced akathisia and dystonia triggered by alcohol." JAMA, 236, p. 2422-3
- Freed E (1981) "Alcohol-triggered-neuroleptic-induced tremor, rigidity and dystonia." Med J Aust, 2, p. 44-5
phenylephrine food
Applies to: Phenergan VC (phenylephrine / promethazine)
MONITOR: Coadministration of two or more sympathomimetic agents may increase the risk of adverse effects such as nervousness, irritability, and increased heart rate. Central nervous system (CNS) stimulants, particularly amphetamines, can potentiate the adrenergic response to vasopressors and other sympathomimetic agents. Additive increases in blood pressure and heart rate may occur due to enhanced peripheral sympathetic activity.
MANAGEMENT: Caution is advised if two or more sympathomimetic agents are coadministered. Pulse and blood pressure should be closely monitored.
References
- Rosenblatt JE, Lake CR, van Kammen DP, Ziegler MG, Bunney WE Jr (1979) "Interactions of amphetamine, pimozide, and lithium on plasma norepineophrine and dopamine-beta-hydroxylase in schizophrenic patients." Psychiatry Res, 1, p. 45-52
- Cavanaugh JH, Griffith JD, Oates JA (1970) "Effect of amphetamine on the pressor response to tyramine: formation of p-hydroxynorephedrine from amphetamine in man." Clin Pharmacol Ther, 11, p. 656
- (2001) "Product Information. Adderall (amphetamine-dextroamphetamine)." Shire Richwood Pharmaceutical Company Inc
- (2001) "Product Information. Tenuate (diethylpropion)." Aventis Pharmaceuticals
- (2001) "Product Information. Sanorex (mazindol)." Novartis Pharmaceuticals
- (2001) "Product Information. Focalin (dexmethylphenidate)." Mikart Inc
- (2002) "Product Information. Strattera (atomoxetine)." Lilly, Eli and Company
maraviroc food
Applies to: maraviroc
Administration with food may reduce the bioavailability of maraviroc. According to the product labeling, coadministration of a 300 mg dose of maraviroc with a high-fat breakfast reduced maraviroc peak plasma concentration (Cmax) and systemic exposure (AUC) by 33% in healthy volunteers. However, no food restrictions were used in the clinical studies that demonstrated the safety and efficacy of maraviroc. Therefore, maraviroc can be taken with or without food at the recommended dosage.
References
- (2007) "Product Information. Selzentry (maraviroc)." Pfizer U.S. Pharmaceuticals Group
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.
See also
Drug Interaction Classification
Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
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. | |
No interaction information available. |
Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Check Interactions
To view an interaction report containing 4 (or more) medications, please sign in or create an account.
Save Interactions List
Sign in to your account to save this drug interaction list.