As temperatures are set to rise again across the UK, there is a critical rule that anyone using amitriptyline for pain or migraine must follow. The commonly prescribed medication, used by millions for nerve pain, migraine prevention, and depression, requires careful storage to remain effective.
Why Storage Matters
Amitriptyline was first licensed in the 1960s as an antidepressant, but today it is more frequently prescribed for nerve pain and migraine prevention. In 2022-23, over 15 million items of the drug were dispensed in the UK. Higher doses are typically used for depression, while lower doses are common for pain relief. Patients are advised to take it at night due to drowsiness, and to limit alcohol if it increases sleepiness.
Common side effects include constipation, dizziness, dry mouth, sleepiness, difficulty urinating, and headache. However, as summer temperatures rise, a lesser-known rule becomes vital.
The 25°C Rule
According to the amitriptyline patient leaflet, the medication must be stored below 25°C in a dry place, protected from light. This weekend, parts of the UK are forecast to reach 32°C, with the UK Health Security Agency issuing an amber heat health alert for several regions until June 23.
The Medicines and Healthcare products Regulatory Agency has warned that heat can break down active ingredients in medicines, potentially making them less effective. This applies to tablets, inhalers, hormone patches, insulin, and EpiPens. Cars, trains, buses, and even bags can become hot enough to cause damage.
Signs of heat damage include changes in colour, smell, or texture. If you notice any, consult your pharmacist. At home, store medicines in the coolest part of the house, away from direct sunlight. When travelling, avoid leaving them in warm vehicles or bags; a cool bag can help on hot days.
Heat damage can also affect how your body absorbs the medicine, making your dose too strong or too weak. If you notice changes in how you feel or how well your medicine works during hot weather, speak to your pharmacist or doctor.
