Skip to main content

Drug Interactions between atovaquone / proguanil and pyrimethamine

This report displays the potential drug interactions for the following 2 drugs:

Edit list (add/remove drugs)

Interactions between your drugs

Moderate

pyrimethamine proguanil

Applies to: pyrimethamine and atovaquone / proguanil

MONITOR: Coadministration of pyrimethamine with other antifolate or myelosuppressive agents may have additive effects on rapidly proliferating tissues such as bone marrow, possibly increasing the risk of megaloblastic anemia and other hematologic adverse effects.

MANAGEMENT: Caution is advised if pyrimethamine is prescribed in combination with other antifolate or myelosuppressive agents. Complete blood cell counts should be closely monitored. Treatment interruption or dose reduction may be required if toxicities such as mucositis or myelosuppression develop. Patients should be advised to contact their physician if they develop oral ulcers, painful swallowing, vomiting, diarrhea, and/or signs and symptoms of myelosuppression such as pallor, dizziness, fatigue, lethargy, fainting, easy bruising or bleeding, or signs of infection such as fever, chills, sore throat, body aches, and other influenza-like symptoms.

References (2)
  1. "Multum Information Services, Inc. Expert Review Panel"
  2. Cerner Multum, Inc. "UK Summary of Product Characteristics."

Drug and food interactions

Moderate

atovaquone food

Applies to: atovaquone / proguanil

ADJUST DOSING INTERVAL: Food, particularly high-fat food, significantly enhances the oral absorption and bioavailability of atovaquone. In 16 healthy volunteers, administration of a single 750 mg dose of atovaquone suspension following a standard breakfast (23 g fat: 610 kCal) resulted in an approximately 3.4-fold increase in the mean peak plasma concentration (Cmax) and a 2.5-fold increase in the mean area under the plasma concentration-time curve (AUC) of atovaquone compared to administration following an overnight fast. In a study consisting of 19 HIV-infected volunteers receiving atovaquone suspension 500 mg/day, Cmax and AUC of atovaquone increased by 72% and 66%, respectively, in the fed state relative to the fasting state.

MANAGEMENT: To ensure maximal oral absorption, atovaquone products (suspension, tablet, or in combination with proguanil) should be administered with a meal or milky drink, or enteral nutrition at the same time(s) each day. Because plasma atovaquone concentrations have been shown to correlate with the likelihood of successful treatment and in some cases, survival, alternative therapies may be appropriate for patients who have difficulty taking atovaquone with food.

References (3)
  1. (2001) "Product Information. Mepron (atovaquone)." Glaxo Wellcome
  2. (2001) "Product Information. Malarone (atovaquone-proguanil)." Glaxo Wellcome
  3. Wohlt PD, Zheng L, Gunderson S, Balzar SA, Johnson BD, Fish JT (2009) "Recommendations for the use of medications with continuous enteral nutrition." Am J Health Syst Pharm, 66, p. 1438-67

Therapeutic duplication warnings

Therapeutic duplication is the use of more than one medicine from the same drug category or therapeutic class to treat the same condition. This can be intentional in cases where drugs with similar actions are used together for demonstrated therapeutic benefit. It can also be unintentional in cases where a patient has been treated by more than one doctor, or had prescriptions filled at more than one pharmacy, and can have potentially adverse consequences.

Duplication

Antimalarials

Therapeutic duplication

The recommended maximum number of medicines in the 'antimalarials' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'antimalarials' category:

  • atovaquone/proguanil
  • pyrimethamine

Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.

See also

Report options

Loading...
QR code containing a link to this page

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.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer