Dosulepin

What is dosulepin?

Dosulepin (also known by brand names such as Dothiepin and Prothiaden) is a type of antidepressant from the tricyclic antidepressant (TCA) group. While it was once widely used to treat depression, it is now prescribed far less often due to safety concerns – particularly the high risk if taken in overdose. Unless specifically recommmended by a specialist, it is no longer prescribed to new patients. However, it may still be prescribed in some cases for depression, nerve pain, or migraine prevention[1]. 

What is dosulepin used for?

Doctors may prescribe dosulepin for[1]: 

• Depression (usually if other treatments have not worked or if you have taken it for an extended period of time) 

• Nerve pain (neuropathic pain) such as fibromyalgia or migraines 

Despite these uses, it is no longer recommended as a first-line treatment for depression because of its potential risks[1]. 

How does dosulepin work?

Dosulepin increases the levels of mood-regulating chemicals in the brain, such as serotonin and noradrenaline. These changes can help lift mood, reduce anxiety, and relieve nerve-related pain. It also has a sedative effect, which can help with sleep in people who are depressed or in pain[1]. 

Who can take dosulepin?

Dosulepin is generally only prescribed for adults. You should speak to your doctor if you[1]: 

• Have certain heart conditions or a recent heart attack 

• Have severe liver disease 

• Have epilepsy or a history of seizures 

• Have bipolar disorder 

• Have porphyria 

• Have kidney problems 

• Have glaucoma 

• Have suicidal thoughts or tendencies 

• Are pregnant, trying to get pregnant, or are breastfeeding 

Please tell your doctor or pharmacist about any conditions you may have or medication you take before you start treatment, and always follow the instructions in the Patient Information Leaflet[2].  

What is the typical dosage of dosulepin?

Dosulepin comes in 2 different strengths: 25mg capsules or 75mg tablets. It is usually taken once a day, typically at bedtime, due to its sedating effects. The usual daily dose ranges from 75mg to 150mg, with your doctor possibly starting you on a lower dose and adjusting as needed[1]. 

How do you take dosulepin?

Take dosulepin exactly as prescribed. It can be taken with or without food, and the tablets should be swallowed whole with water. Do not crush or chew them. You should take it at the same time each day, usually at bedtime, and never stop the medicine suddenly without medical guidance[1]. 

Can you stop taking dosulepin?

You should not stop dosulepin suddenly unless advised by your doctor or pharmacist. Doing so can cause withdrawal symptoms, including headaches, nausea, irritability, flu-like symptoms, and anxiety. Your doctor will help you gradually reduce your dose to avoid these effects safely[1]. 

What do you do if you take too much dosulepin?

Dosulepin overdose is extremely serious and can be fatal. If you or someone else takes too much – even by accident – seek emergency medical attention immediately. Signs of overdose may include confusion, seizures, an irregular heartbeat, or loss of consciousness[1].  

What do you do if you forget to take dosulepin?

If you miss a dose, take it as soon as you remember. If it's close to your next scheduled dose, skip the missed dose and continue as normal. Do not take a double dose to make up for a missed one[1]. 

How do you store dosulepin?

Store dosulepin in a cool, dry place away from heat and direct sunlight. Keep it in its original packaging and out of the reach of children. Do not use it after the expiry date printed on the label[1].  

What medicines can’t you take with dosulepin?

Dosulepin can interact with several medications, so it’s important to let your doctor or pharmacist know about anything else you’re taking, particularly[1]: 

• Other antidepressants (especially MAOIs) 

• Beta-blockers or other heart medications 

• Antihistamines that cause drowsiness 

• Alcohol, which increases the risk of side effects like sedation 

• Herbal products like St John’s Wort 

Always inform your doctor or pharmacist about all medications and supplements you take before you start a new medicine, and follow the instructions in the Patient Information Leaflet[2]. 

What are the side effects of dosulepin?

Like all medicines, dosulepin can cause side effects. Some are more common and mild, while others are rare but serious. Common side effects include[1]: 

• Dry mouth 

• Drowsiness or feeling sleepy during the day 

• Constipation 

• Dizziness or blurred vision 

• Weight gain 

• Headaches 

Serious side effects[1]: 

• Irregular heartbeat or palpitations 

• Seizures 

• Constant headaches or confusion 

• Severe constipation or inability to pee 

• Worsening depression or suicidal thoughts 

You should contact your GP if you experience any of these symptoms. In rare cases, the medicine may cause a serious allergic reaction (anaphylaxis). You should call 999 or visit A&E immediately if you believe this is happening[1]. 

Symptoms of anaphylaxis include[1]:  

• Difficulty breathing  

• Tightness in throat and chest  

• Swelling of the tongue or throat  

• Feeling faint or dizzy  

• Blue/grey skin or lips  

• Loss of consciousness 

If you experience any side effects, including those not listed, you are encouraged to report them via the Yellow Card Scheme or contact your doctor, pharmacist, or nurse. This information is intended as a summary for general awareness and does not replace professional medical advice. 

The information provided in the side effects section is not a comprehensive list of all possible side effects associated with this medication. For a complete list of side effects, please refer to the Patient Information Leaflet (PIL) provided with your medication or consult your healthcare professional[2]. 

Frequently asked questions about dosulepin

Why is dosulepin no longer commonly prescribed? 
Due to its high risk in overdose and the availability of safer alternatives, dosulepin is now usually only prescribed when other treatments haven’t worked[1]. 

Is dosulepin addictive? 
It’s not considered addictive but suddenly stopping it can cause withdrawal symptoms. Always stop gradually under medical supervision[1]. 

Can I drink alcohol while taking dosulepin? 
It’s best to avoid alcohol, as it can worsen side effects like drowsiness and dizziness[1]. 

How long does dosulepin take to work? 
It may take 2 to 4 weeks to feel the full benefit. Keep taking it as directed, even if you don’t notice changes straight away[1]. 

Can dosulepin be used for anxiety? 
It’s sometimes used when anxiety is linked to depression, but it’s not a first-choice treatment[1]. 

Is it safe during pregnancy or breastfeeding? 
It’s generally not recommended. If you're pregnant or breastfeeding, consult your doctor for safer options[1]. 

Can I drive while taking dosulepin? 
Avoid driving or operating heavy machinery if you feel drowsy, dizzy, or have blurred vision[1]. 

What should I do if I feel worse while taking it? 
Tell your doctor immediately – do not stop taking it suddenly[1]. 

What are the alternatives to dosulepin? 
Newer and safer antidepressants, such as SSRIs (e.g. sertraline or fluoxetine), are usually tried first[1]. 

For the official NHS guide to dosulepin, visit their website.