Q4

Question 1

Trimethoprim-Sulfamethoxazole

Answer 1

Serious allergic reaction to trimethoprim—contraindicated.

Contraindicated if CrCl <10 mL/minute; reduce dose if CrCl 10–30 mL/minute
Avoid use in elderly - risk of severe AE
Don’t use in pregnancy - trimethoproim not indicated in 1st trimester, sulfamethoxazole is contraindicated in late pregnancy
contraindicated in severe hepatic impairment
Sulfonamides increase the risk of haemolysis in G6PD deficiency.

Monitor: complete blood count and folate status, renal function, serum potassium
Common AE: nausea, vomiting, hyperkalaemia
Rare AE: megaloblastic anaemia, depression, Stevens-Johnson syndrome
Counselling:
- Take this medicine with food to reduce stomach upset.
- Drink a lot of fluid (at least 2–3 L daily) during prolonged or high-dose treatment.
- To reduce risk of rash from the sun avoid sun exposure, wear protective clothing and use sunscreen.
- Tell your doctor straight away if you get a sore throat, fever, troublesome rash, cough, difficulty in breathing, joint pain, dark urine or pale stools.

Question 2

Amoxicillin

Answer 2

Be mindful of penicllin allergies. Be careful if there is carbapenem or cephalosporin allergy as cross-reactivity between penicillins, cephalosporins and carbapenems can occur. Adjust dose in renal impairment.

Monitor: allergies, renal impairment
Common AE: nausea, diarhoea
Rare AE: black tongue, electrolyte disturbances, Stevens-Johnson syndrome
Counselling: This medication commonly causes diarrhoea, if you experience this it does not mean you are allergic to the medication.
Do not take more doses than prescribed. If you have medication left after finishing your course, dispose of them at your local pharmacy. Do not save them for a later infection.
RASH?????????????