You are a hospital pharmacist who provides antibiotics services. A 72-year- old man has just been diagnosed with pulmonary tuberculosis infection. He has a known medical history of chronic obstructive airway disease, diabetes mellitus, and atrial fibrillation. His body weight is 60 kg. He has moderately impaired renal function (creatinine clearance 40 mL/min). His current medication includes salbutamol 2 puffs 4 times daily, Trelegy Ellipta (fluticasone 100 mcg, umeclidinium 62.5 mcg, vilanterol 25 mcg) 1 puff daily, glimepiride 2 mg daily, metformin 500 mg twice daily, metoprolol 25 mg twice daily, and dabigatran 110 mg twice daily. 

(a) What are the initial recommended conventional anti-tuberculosis drugs in a THRICE-WEEKLY REGIME (dosage and duration) for the patient? 

(3 marks)

I speculate the point distribution to be:

• 1 point for naming all 4 drugs
• 1 point for dosages
• 1 point for durations

Can use the mnemonic RIPE to help remember the first line TB drugs

The drugs used and the durations are the same for the daily and the thrice weekly regimens. For the dosages a strategy you can use to try to remember is to compare the daily doses with the thrice weekly doses and look for similarities and relationships.

Initial and continuation phase:

• Isoniazid 15 mg/kg (max 900 mg) three times a week for 6 months (vs daily dose 300 mg)
• Rifampicin 600-900 mg three times a week for 6 months (vs daily dose 450 mg)

Initial phase only:

• Pyrazinamide body weight 50 kg and above 2.5 g three times a week for 2 months (vs daily dose 2g)
• Ethambutol 30 mg/kg three times a week for 2 months (vs daily dose 15mg/kg)

Doses to be rounded up to suit available tablet strengths, except for ethambutol because of risk of optic neuropathy.

Please review previous TB questions:

• https://www.pharmacyexamquestions.com/courses/pharmacy-practice-dec-2021/lectures/39233549
  
• https://www.pharmacyexamquestions.com/courses/1531478/lectures/35283586
  

BNF