About the shortage of Catapres (clonidine) 150 mcg tablets

Summary

• Catapres (clonidine) 150 mcg tablets were in shortage between December 2025 and March 2026.
• An SSSI was made to allow pharmacists to substitute Catapres 150 mcg tablets with clonidine 100 mcg tablets, if appropriate, without a prescription.
• A further shortage was anticipated during May 2026. In response, the SSSI was extended until 28 June 2026.
• This shortage is no longer expected to occur, and the information below may no longer be relevant. 

Pharmaceutical company Clinect told us that Catapres (clonidine) 150 microgram (mcg) tablets would be in shortage between 4 May and 31 May 2026 due to an increase in demand. The shortage is no longer expected to occur. See Summary above for details and note that the information below may no longer be relevant.

Catapres 150 mcg is the only brand of clonidine 150 mcg tablets supplied in Australia and is used to treat essential hypertension and renal hypertension. Clonidine is also used off-label for various conditions, including attention deficit hyperactivity disorder (ADHD), chronic pain and cancer pain.

The lower-strength clonidine 100 mcg tablets remain available. To help patients have continuous access to their medicine during the shortage, we extended the Serious Scarcity Substitution Instrument (SSSI) to 28 June 2026. The SSSI allows a pharmacist to dispense an equivalent quantity of clonidine 100 mcg tablets, if appropriate, without a new prescription.

To make up a substitute dose, the patient would need to break or cut a 100 mcg tablet in half.

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 ‘Catapres 150’).

Information for patients

If the Catapres (clonidine) 150 mcg tablets your doctor has prescribed are not available, your pharmacist can substitute clonidine 100 mcg tablets without needing a new prescription. This may mean you will need to switch between different brands or strengths of clonidine tablets. Please note:

• The substitute medicines contain a different strength of the same active ingredient that your doctor prescribed, and the pharmacist will supply the correct total dose for you.
• All of the products contain the same medicine (clonidine) and are taken by mouth, but the strength is different.
• Talk to your doctor or pharmacist if you have any questions about this substitution.
• As excipients (inactive ingredients) vary between brands, tell your pharmacist if you are allergic or intolerant to certain ingredients. You can also find information about excipients in the Consumer Medicine Information (CMI) leaflet for the medicine, which is available from your pharmacist or on the TGA website (go to ‘Search for health products on our register’ on the homepage).

If your pharmacist gives you clonidine 100 mcg tablets as a substitute, they will explain to you the differences and how to take them:

• The tablets are a different strength and might look different.
• You may need to break or cut a 100 mcg clonidine tablet exactly in half to get the dose you have been prescribed.

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 clonidine 100 mcg tablets for someone with a prescription for clonidine 150 mcg tablets. You can do this 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 the patient, and to gain their consent. Always refer patients to their prescriber if:

• substitution is inappropriate
• an appropriate substitutable medicine is not available.

It may not be appropriate for all patients prescribed clonidine 150 mcg to receive clonidine 100 mcg. Situations where substitution is inappropriate could include when a patient:

• does not have the dexterity needed to comfortably break or cut the 100 mcg tablets, if needed, either because of their age or medical conditions
• has cognitive, visual or hearing impairments that could make substituting their medicine difficult.

It is important to note that inadvertent overdose may occur if the tablet is inaccurately split. In some cases, 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 or carer on how to take or give the substitute medicine, or refer them to their prescriber, GP or nurse for guidance
• you can use Consumer Medicine Information (CMI) leaflets to help explain the substitution to patients or their carers and to gain their consent; you may need to use translation services, a carer or organisations such as a local Aboriginal Community Controlled Health Organisation (ACCHO) to ensure the patient fully understands the situation.

You can find information on Pharmaceutical Benefits Scheme (PBS) subsidy arrangements for medicines substituted using an SSSI on the PBS website.

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

Information for prescribers

Consider the shortage of clonidine 150 mcg tablets when prescribing for your patients, particularly when initiating new patients.

Your patients may need to switch between different brands or strengths of clonidine tablets when the prescribed medicine is unavailable.

Patients prescribed clonidine 150 mcg tablets may be given clonidine 100 mcg tablets by their pharmacist to make up their daily dose, or they may be referred to you to review their needs.

Consider checking how your patient is managing the substitution medicine at their next appointment.

With the SSSI in place, a pharmacist may substitute the prescribed clonidine 150 mcg tablets with clonidine 100 mcg tablets and give the patient information and guidance on how to administer the substitute product, or they may recommend the patient contact you for this information.

The pharmacist will refer the patient to you if:

• an appropriate substitutable medicine is not available
• they feel a medicine is not clinically appropriate for a patient, or alternative treatments other than substitution may be more appropriate
• the patient does not consent to the substitution
• you have noted on the prescription that substitution is not permitted.

The pharmacist will also refer the patient to you if substitution is inappropriate, for example if the patient:

• does not have the dexterity needed to comfortably break or cut the 100 mcg tablets, if needed, either because of their age or medical conditions
• has cognitive, visual or hearing impairments that could make substituting their medicine difficult.

They may do this noting that inadvertent overdose may occur if the tablet is inaccurately split.

General information

Please note that the dates given for a shortage may change and we encourage you to check the Medicine shortage reports database for updates about the supply of Catapres (clonidine hydrochloride) 150 mcg 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.

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 Catapres (clonidine) 150 mcg tablets and 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.