About the shortage of Presolol 100 (labetalol hydrochloride 100 mg) tablets

Pharmaceutical company Alphapharm has advised that Presolol 100 (labetalol hydrochloride 100 mg) tablets will remain in shortage until mid-November 2025 due to manufacturing issues. The alternative strength of Presolol 200 (labetalol hydrochloride 200 mg) tablets is available.

Labetalol is used to treat all grades of hypertension.

To help patients access this essential medicine, we made a Serious Scarcity Substitution Instrument (SSSI) that allows a pharmacist to substitute the prescribed labetalol 100 mg with labetalol 200 mg, if appropriate, without a new prescription. We have extended the SSSI until 31 December 2025 because the shortage has been extended.

With the substitution, one tablet of Presolol 100 (labetalol 100 mg) is equivalent to half a tablet of Presolol 200 (labetalol 200 mg).

See below for information about the SSSI for patients, pharmacists and prescribers.

Up-to-date information about the shortage is published on the Medicine Shortage Reports Database. Search for ‘Presolol 100’.

Information for patients

If you are prescribed Presolol 100 (labetalol hydrochloride 100 mg) and it is not available, your pharmacist can substitute Presolol 200 (labetalol hydrochloride 200 mg) tablets without a new prescription. 

If your pharmacist gives you Presolol 200 (labetalol hydrochloride 200 mg) tablets in place of the 100 mg tablet, they will explain that: 

• the tablets might look different because they are a different strength
• you should break a 200 mg Presolol tablet in half and take only one of the halves to get a 100 mg dose
• if the tablet is not split exactly in half, you are at risk of inadvertent overdose, which could cause your blood pressure to drop suddenly.

Please note that:

• the substitute medicine may cost you more, as the Presolol 200 (labetalol hydrochloride 200 mg) tablets are not on the Pharmaceutical Benefits Scheme (PBS)
• once a script is changed to private to get 200 mg tablets during the shortage, it cannot be used as a PBS script for repeats in the future − the pharmacist will tell you about this
• you may still need a new prescription from your doctor if you cannot comfortably break the tablet exactly in half, if the substitute tablets are not available, or if another treatment would be better for you.

If you are unable to fill your prescription or do not consent to the substitution, speak to your doctor about other options for your situation.

Information for pharmacists

The SSSI allows you to substitute Presolol 200 (labetalol hydrochloride 200 mg) tablets for someone with a script for Presolol 100 (labetalol hydrochloride 100 mg) tablets, without prior approval from the prescriber, if you follow the Specific permitted circumstances (in Schedule 1) and General permitted circumstances (in Schedule 2) of the SSSI.

You are encouraged to use your professional and clinical judgement to determine whether substitution is suitable for a patient and to gain their consent. Refer patients to the prescriber if: 

• substitution is inappropriate, for example if the patient does not have the dexterity or cognitive capacity needed to comfortably break the 200 mg tablets, either because of their age or medical conditions; if the tablet is inaccurately split, the patient is at risk of inadvertent overdose, which could cause postural hypotension
• an appropriate substitutable medicine is not available
• alternative treatments other than substitution may be more appropriate.

When you use the SSSI to substitute the scarce and substitutable medicine: 

• you must instruct the patient on how to take the substitute tablet, or refer them to their prescriber or GP for guidance
• you can use Consumer Medicines Information (CMI) leaflets to help explain the substitution to patients and to get their consent; you may need to use translation services, a carer or organisations such as a local Aboriginal Community Controlled Health Organisation (ACCHO) if needed to ensure the patient fully understands the situation. 

Dispensing labetalol 200 mg tablets under this SSSI will affect PBS subsidisation. Please consider and discuss with your patients that Presolol 200 (labetalol 200 mg) tablets are not listed on the PBS. If a patient has a PBS prescription for Presolol 100 (labetalol 100 mg) tablets and you dispense Presolol 200 (labetalol 200 mg) tablets as a substitutable medicine, they will not get a PBS subsidy. Also, dispensing a PBS prescription as private means future repeats cannot be dispensed under the PBS. 

Inform the prescriber by email, fax or phone as soon as is practical after you make the substitution. 

Information for prescribers

Consider the current shortage of Presolol 100 (labetalol hydrochloride 100 mg) tablets when prescribing for your patients, particularly when initiating new patients. 

Your patients prescribed a dose of labetalol hydrochloride 100 mg may need to get Presolol 200 (labetalol hydrochloride 200 mg) and take half a tablet during the shortage.

With the SSSI in place, a pharmacist may substitute the prescribed Presolol 100 (labetalol hydrochloride 100 mg) tablets with Presolol 200 (labetalol hydrochloride 200 mg) tablets without a new prescription from you.

When a pharmacist offers your patient the substitute strength, they may give information and guidance on how to take it, or they may recommend the patient contact you for this information. Consider checking how your patient is using the substitute strength at their next appointment. 

The pharmacist will refer the patient to you if: 

• they consider the substitution to be inappropriate, for example if the patient does not have the dexterity or cognitive function needed to comfortably break the 200 mg tablets, noting that inadvertent overdose may occur if the tablet is inaccurately split
• an appropriate substitutable medicine is not available
• the patient does not consent to the substitution
• alternative treatments other than substitution may be more appropriate.

Please note that Presolol 200 (labetalol hydrochloride 200 mg) tablets are not subsidised on the PBS and would not be subsidised under the SSSI. Also, if a PBS prescription is dispensed as private, future repeats cannot be dispensed under the PBS. 

Your patient may prefer a new prescription for a medicine that is subsidised on the PBS.

General information

Please note that the dates given for this shortage may change and we encourage you to check the Medicine shortage reports database for updates about the supply of Presolol 100 (labetalol hydrochloride 100 mg) tablets.

Please also keep in mind that we can work with pharmaceutical companies to communicate information about medicine shortages to health professionals and patients, but we cannot compel companies to increase supply or apply to have their products subsidised on the PBS.

While we can suggest approaches to manage the supply of medicines during shortages, we do not have the power to regulate the clinical decisions of health professionals.

We will continue to monitor the supply of Presolol 100 (labetalol hydrochloride 100 mg) tablets and work with the supplier to update this advice if needed.

Reporting problems

Consumers and health professionals are encouraged to report problems with medicines or vaccines. Your report will contribute to the TGA's monitoring of these products.

The TGA cannot give advice about an individual's medical condition. You are strongly encouraged to talk with a health professional if you are concerned about a possible adverse event associated with a medicine or vaccine.