Drug interactions between cimetidine and Viagra
| Results for the following 2 drugs: |
|---|
| cimetidine |
| Viagra (sildenafil) |
Interactions between your selected drugs
cimetidine ↔ sildenafil
Applies to:cimetidine and Viagra (sildenafil)
MONITOR: Coadministration with cimetidine may increase the plasma concentrations of sildenafil. The mechanism is cimetidine inhibition of sildenafil metabolism via CYP450 isoenzymes in the intestinal wall and liver. In one study, 20 healthy male volunteers received a single 50 mg dose of sildenafil on days 1 and 5, and either cimetidine 800 mg or placebo on days 3, 4, 5, and 6. Coadministration of cimetidine caused a statistically significant increase in sildenafil peak plasma concentration (Cmax) and area under the plasma concentration-time curve (AUC) of 54% and 56%, respectively, compared to placebo. Cimetidine also increased the AUC of sildenafil's major metabolite by 30%. Sildenafil was well tolerated either alone or in combination with cimetidine in the study, and no clinically significant changes in blood pressure and pulse rate or abnormalities in ECG were reported.
MANAGEMENT: Based on the magnitude of the reported interaction, no dosage adjustment for sildenafil should be necessary during coadministration with cimetidine. However, patients should be advised to promptly notify their physician if they experience potential signs and symptoms of sildenafil toxicity such as pain or tightness in the chest or jaw, irregular heartbeat, nausea, shortness of breath, visual disturbances, syncope, or prolonged erection (greater than 4 hours).
See also...
Drug Interaction Classification
The classifications below are a guideline only. The relevance of a particular drug interaction to a specific patient is difficult to determine using this tool alone given the large number of variables that may apply.
| 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. |
Do not stop taking any medications without consulting your healthcare provider.
Disclaimer: Every effort has been made to ensure that the information provided by Multum is accurate, up-to-date, and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. Multum's drug information does not endorse drugs, diagnose patients, or recommend therapy. Multum's drug information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug of drug combination is safe, effective, or appropriate for any given patient. Multum Information Services, Inc. does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. Copyright 2000-2012 Multum Information Services, Inc. The information in contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse, or pharmacist.
