Rifinah 100/150 mg tablets (isoniazid 100 mg with rifampicin 150 mg): Supply issue resolved

Reason for issue

Due to manufacturing plant delays, these tablets were temporarily out of stock from the beginning of April until the mid May 2023.

Alternative option

There are funded alternatives for the two components of Rifinah 100/150 mg tablets, an isoniazid 100 mg tablet (PSM) (pharmacode 267473) and a rifampicin 150 mg capsule (Rifadin) (Pharmacode 251186).

Clinical advice has indicated that it would be appropriate to substitute the combination tablet, Rifinah 100/150 mg, with the two individual components, isoniazid 100 mg tablets and rifampicin 150 mg capsules.  

What this means for people using Rifinah 100/150mg

Rifinah 100/150 mg is a combination tablet made up of isoniazid 100 mg and rifampicin 150 mg. There are funded alternatives for both of these medicines, an isoniazid 100 mg tablet (PSM brand), and a rifampicin 150 mg capsule (Rifadin brand), which may mean you need to take one tablet and one capsule instead of your usual combination tablet.

Your prescriber, pharmacist, or public health nurse will let you know how many tablets you need to be taking.

We know that increasing the number of pills you take is inconvenient; however, this is necessary to continue receiving your treatment while the supplier of your usual combination tablet works through this manufacturing issue.

Medicines to treat tuberculosis are free in New Zealand, so this change will not mean you have to pay more at the pharmacy.

Actions for prescribers and public health staff 

• When prescribing Rifinah 100/150 mg, there is no need to alter the prescription. Rule 3.4.2 of the Schedule Rules(external link) allows a pharmacist to dispense what presentation they have in stock, without altering the dose, frequency and/or total daily dose dispensed.
• Counsel people using Rifinah 100/150 mg tablets that due to this temporary supply issue, between now and May 2023, they may receive either a combination tablet or one tablet and one capsule to make up their next prescription.

Actions for pharmacists

• As per Rule 3.4.2 of the Schedule Rules(external link), if you receive a prescription for Rifinah 100/150 mg and cannot source stock, you can substitute 1x isoniazid 100 mg tablet and 1x rifampicin 150 mg capsule in place of each Rifinah tablet prescribed, provided you do not alter the dose, frequency and/or total daily dose dispensed, without needing a new prescription from the prescriber.

• Counsel people prescribed this medicine on the presentation you are dispensing and how many tablets/capsules they need to take, as this may differ from their previous prescription, and let them know that this is a temporary supply issue with the combination tablet, Rifinah 100/150 mg, expected to be back in stock in May 2023.

Key dates

1 April 2023

• Rifinah 100/150 mg (251532) is out of stock at the supplier level.

24 April 2023

• The next shipment of Rifinah 100/150 mg (251532) is expected to arrive in the country. This stock will take about a week to move through the supply chain to pharmacies.

11 May 2023

• Rifinah 100/150 mg is available.

Who to contact

If you have questions about this supply issue, please email enquiry@pharmac.govt.nz