Little TV Addict

A question from my tutor prompt me to read up on oral contraceptives and their interactions. I’v always known there is some sort of interactions with antibiotics and with liver enzyme inducing drugs, however, what I knew probably wasn’t good enough to pass exams. Anyway here is just a recap/prompt for you to look it up and read more about it.

 

Does flucloxacillin interacts with the combined oral contraceptive pill?

Does flucloxacillin suppresses the gut flora?

 

 

Main points are highlighted in RED.

Part I – Liver Enzyme Inducing drugs i.e. Rifampicin (reduces effectiveness of oral contraceptives)

Short Course : Need to adjust pill to provide 50mcg ethinylestradiol or more daily, additional contraceptive protection, and continue for 4 weeks after stopping LEI drug.

Long-term Course : Consider contraceptive method not affected by liver enzymes, if no alternative, provide 5omcg ethynylestradiol or more daily, and tricycling recommended

*Tricycling - taking 3 or 4 packs of monophasic tabs without a break followed by 4 days pill free period.

Part II – Antibiotics that do not induce liver enzymes (reduce effectiveness of pill by imparing gut flora responsible for oestrogen recycling)

Additional protection required during Abx course, and continue for 7 days after completing Abx, if the 7 days run beyond the end of cycle, start next cycle immediately, for ED tabs, omit the inactive tabs.

* If Abx Tx more than 3 weeks, dont need additional protection due to bacterial resistance

List of Abx affected (non-enzyme inducing)

• Rifampin (the only enzyme inducing antibiotic affecting pills)
• Ampicillin
• Sulfamethoxazole
• Nitrofurantoin
• Penicillin
• Tetracycline
• Amoxicillin

Finally, after 9 long months working in the dispensary, I get to work on the counter for a bit. So I have learnt something new today, would like to share it with you, and also I think jotting it down can help me enhance my memory.

Scenario

A middle aged lady in her 50′s asked for some cream for athlete’s foot. So upon going through all the WHAMM (questioning of when, how, age, medication history etc), I found out she is on warfarin. As we all know warfarin interacts with an awful lot of medications. Many pharmacists prefers to refer them to the doctor instead of offering any products over the counter. So knowing that she wants some cream for athlete’s foot, and she is on warfarin, what would be the most appropriate cream for her??

Comments

 

We all know that athlete’s foot is a fungal infection, so antifungal cream would treat it, but we have got several to choose from. One of my top recommendation would be Daktarin Gold (Ketoconazole 2% cream), other available creams are Daktarin cream (Miconazole) and Canestan cream (Clotrimazole 1%) or even Lamisil (Terbinafine). Forget about Lamisil because its too pricey. Upon checking Stockleys drug interactions and BNF (british national formulary), I found out that ketoconazole and miconazole (creams are absorbed into the bloodstream) both increases the plasma concentration of warfarin(thins the blood), which increases the risk of bleeding. So I offered Clotrimazole 1% cream (canestan).

Directions of use

Clean and dry feet, apply cream 2-3 times a day for at least 2 weeks, and up to 4 weeks. Many customers experience recurrent problems, an antifungal powder would be useful to prevent further infections. Powder can be sprinkled on shoes and socks, and if using it as a treatment, it should be sprinkled between toes, and all over the feet. It is advisable to also change stockings/socks daily for people who have recurrent fungal infections.

Hope this article was helpful for some of you.