Pill Interactions with Other Drugs
Oral Contraceptives (OC) May Interfere with the Following Medications:
| MEDICATION | SIGNIFICANCE† | ADVERSE EFFECTS | RECCOMENDATIONS |
|---|---|---|---|
CORTICOSTEROIDS: |
• • • • | Some steroids have reduced metabolism and higher blood levels when combined with OCs. | A reduction in steroid dose may be required. |
THEOPHYLLINE: |
• • • • | OCs may raise blood levels of theophylline. | The theophylline level will need to be monitored. |
BENSODIASEPINES: |
• • • | OCs may raise blood levels of benzodiazepines. | A reduction in dose of benzodiazepines may be indicated. |
CAFFEINE |
• • • | OCs may reduce the metabolism of caffeine. | Watch for signs of caffeine overdose. |
BETA-BLOCKERS: |
• • | OCs may raise blood levels of beta-blockers. | Monitor heart rate. Monitor dose of beta-blocker. |
TRICYCLIC ANTIDEPRESSENTS: |
• | OCs may raise the blood levels of some tricyclic antidepressants. | Monitor the response to the tricyclic antidepressant. |
SALICYLATE (Asprin) |
• | OCs may lower the blood levels of salicylates. | Aspirin doses may need to be adjusted upwards for women on maintenance doses of salicylates. |
PAIN RELIEVERS: |
• | OCs may lower the blood levels of acetaminophen. | Acetaminophen and OCs may be used together with little or no risk. |
Nonsteroidal Anit-Inflammatory Drugs (NSAIDs): |
• • • • | ||
CYCLOSPORIN |
• • • • | OCs may raise blood levels of cyclosporine increasing the risk of toxicity. | |
ATORVASTIN (Lipitor) |
• • • • | OCs may raise atorvastin levels | Monitor atorvastin |
† Significance: Rated from highly significant (• • • •) to weakly significant (•).
Medications that May Interact with the Oral Contraceptive (OC):
| MEDICATION | SIGNIFICANCE‡ | ADVERSE EFFECTS | RECCOMENDATIONS |
|---|---|---|---|
SEIZURE MEDICATIONS: |
• • • • | Risk of pregnancy up to 25 times higher in OC users also using anticonvulsants. Potential loss of seizure control when used as anticonvulsant. | Consider using alternative methods, altogether. |
| Lamictal | • • • • | Changes in Lamictal levels; lowered during hormone pills and raised during placebo pills | |
| Sodium valproate (Depakene) | • | Does not appear to interfere with oral contraceptive therapy. | |
CENTRAL NERVOUS SYSTEM: |
• • • • | Increased risk of pregnancy. | Consider using alternative methods, altogether. |
ANTIFUNGAL: |
• • • • | Breakthrough bleeding and unintended pregnancies have been reported. | Consider using alternative methods, altogether. |
Ketoconazole (Nizoral) |
• • | Increase blood levels of OC | |
ANTIBIOTICS: |
• • • • | A high incidence of menstrual irregularities and a 6% pregnancy rate is seen on OCs. | Use an alternative or additional contraceptive method. |
All other antibiotics |
• | Questionable association of increased pregnancy risk. | Consider using backup contraception during antibiotic treatment and for 7 days following treatment. |
ST. JOHN'S WORT |
• • | May lower blood concentration levels of hormones that suppress ovulation. | May lower blood concentration levels of hormones that suppress ovulation. |
ASCORBIC ACID (Vitamin C) |
• | May raise levels of estrogen in the blood. | Estrogen-related side effects may appear with vitamin C>1 gram. |
‡ Significance: Rated from highly significant (• • • •) to weakly significant (•).
