Amoxapine (Asendin)

Amoxapine brand names

Amoxapine is usually sold in the U.S. under the brand name Asendin.

What is Amoxapine prescribed for?

Amoxapine is used to treat people with:

• Depressive disorders, including major depressive disorder
• Anxiety disorders
• Depression in patients with bipolar disorder
• Agitation

Amoxapine is usually classified as a third-line treatment. This means it is only prescribed if courses of SSRIs and SNRIs haven’t had any positive effects. ^[2]

How does amoxapine work?

Amoxapine is a tricyclic antidepressant medication (TCA). It works by restoring the levels of chemicals in your brain that you need for a more balanced mental state. ^[1]

How is Amoxapine usually taken?

Amoxapine is usually given in the form of small pills that you take by swallowing.^[1] Depending on your doctor’s advice, you may be required to take one or more a day. Try to take amoxapine at the same time every day (e.g., just before you go to bed). 

If you miss a single dose, then take it when you realize it. However, if it is close to when you plan to take your next dose, it is okay to skip it. Never take more than your prescribed daily dose to catch up on missed doses.

Follow your doctor’s advice exactly, even if you don’t feel any more symptoms or think the drug isn’t working. Taking any more than you have been prescribed can lead to more severe and potentially dangerous side effects. Again, you should consult your doctor if you need any medical advice.

Amoxapine side effects

Taking amoxapine may cause some side effects. These can be mild side effects that you may need to talk to your doctor about if they are causing problems in your life, as well as more severe side effects that require urgent medical attention. ^{[1] [3]}

Mild side-effects: tell your doctor if these become more severe or don’t go away.

• Nausea
• Changes in appetite
• Weight gain
• Sensitive skin
• Urinary retetnion and constipation
• Abnormally frequent urination
• Excessive sweating
• Dry mouth
• Nightmares
• Weakness or tiredness
• Headaches or dizziness

Severe side-effects: whilst these are very rare (less than 1% of patients), seek medical attention urgently if you experience any of them or any side-effects listed in the IMPORTANT WARNING section of the package insert.

• Muscle stiffness
• Fast or irregular heartbeat
• Shuffling walk
• Breaking out in skin rashes
• Fever
• Uncontrollable shaking/tremors
• Seizures

Amoxapine precautions

Your doctor will likely ask you questions before prescribing amoxapine to make sure the drug is safe for you and to help them establish the correct dosages. ^[1]

• Tell your doctor if you are allergic to amoxapine or its ingredients. You can ask your doctor or pharmacist for the list of ingredients to prevent the risk of an allergic reaction.
• Tell your doctor if you currently take, or have recently stopped taking, MAOIs (Monoamine oxidase inhibitors), as this can cause severe adverse reactions such as confusion, abdominal pain, high blood pressure, and convulsions.
• They will ask about any medication you are currently on and any medical conditions you have. Ensure you thoroughly disclose everything you take, including vitamins, dietary supplements, or herbal medicines, as they may cause adverse effects.
• Tell your doctor if you are breastfeeding, plan to become pregnant, or become pregnant while taking amoxapine. Research suggests that the concentration found in the breast milk of mothers taking amoxapine is a quarter of their dose ^[4].
• Be mindful that some side effects of amoxapine may take longer to show up. For example, don’t drive or operate heavy machinery until you know the side effects. Alcohol may make drowsiness worse.
• If you are over 65, speak to your doctor about any alternative drugs you can take to avoid adverse reactions.

Amoxapine interactions

Currently, no known food groups have negative interactions with amoxapine, and it is recommended that you don’t change your diet while taking them ^[1].

As previously said, do not take amoxapine if you are currently taking MAOIs. It is also recommended that people with Parkinson’s disease do not take amoxapine as it has been shown to make motor symptoms worse in some patients ^[5]

Drinking alcohol while taking amoxapine can increase the drowsiness this medication can cause.

Amoxapine storage

Amoxapine should be kept at room temperature, in a dry place, and its original packaging, as this will usually have a child-locked cap. Don’t keep it in the bathroom or anywhere else that may get wet. Keeping it in a (preferably locked) cupboard out of reach of children is the best place for it. 

What to do if you overdose on amoxapine

In high doses, amoxapine can cause overdoses with severe symptoms, potentially resulting in a loss of consciousness and even death. The main symptoms of tricyclic antidepressant overdoses include: ^[6]

• Irregular or fast heartbeat
• High body temperature
• Sleepiness
• Confusion
• Seizures
• Blurred vision and dilated pupils
• Cardiac arrest
• Kidney failure

If no symptoms have shown within 6 hours, then it is less likely that you will suffer an overdose ^[7]. However, if you think you have taken too many pills, are suffering from any overdose symptoms, or know of anyone that has, it is extremely important to seek urgent medical attention.

If a doctor thinks you are displaying symptoms of an overdose, they will monitor you in intensive care for at least 12 hours. If your ECG has been clear for more than 24 hours, your doctor will likely discharge you. ^[6].