The cytochrome P450 system is a collection of liver enzymes that make up a key pathway for drug metabolism. The system is a major source of important drug interactions. Always check interactions.
Want to find out how 99% of people passed their exams?
A 45 year old who takes warfarin for a mechanical heart valve is admitted with a severe community acquired pneumonia. Although his INR was in range (3-4) on admission, after three days, his INR is checked and is 6.2. Which drug is likely to be responsible? What is the mechanism?
Oops! This section is restricted to members. Click here to signup!
A 24 year old female patient who is on the combined oral contraceptive pill is seen in TB clinic for latent TB. The options for chemoprophylaxis in latent TB are rifampicin and isoniazid for 3 months (usually preferred for younger patients), or isoniazid for 6 months. What are you concerned about and what would be the best option for chemoprophylaxis?
Oops! This section is restricted to members. Click here to signup!
A patient takes doxycycline for malaria prophylaxis whilst travelling in Kenya. Despite this, he develops malaria. He says he did not receive any dietary advice when he was prescribed the doxycycline. Which interactions with food/drink/over-the-counter medicines may be responsible for reduced serum doxycycline levels? What is the mechanism?
Oops! This section is restricted to members. Click here to signup!
A patient presents to ED with chest pain and this trace. What would you do?
Interpretation management