Monoamine oxidase inhibitors

Question 1

Drug class
Monoamine oxidase inhibitors

Answer 1

Antidepressants

Question 2

Generic drug names
Monoamine oxidase inhibitors

Answer 2

Phenelzine
Tranylcypromine

Question 3

MAOI a.k.a.

Answer 3

Monoamine oxidase inhibitors

Question 4

Monoamine oxidase inhibitors a.k.a.

Answer 4

MAOIs

Question 5

Indication
MAOIs

Answer 5

Major depression (third line)
Some anxiety disorders

Question 6

MOA
MAOIs

Answer 6

Nonselective MAOIs irreversibly inhibit monoamine oxidases A and B (MAO‑A and MAO‑B), increasing the synaptic concentrations of adrenaline, noradrenaline, dopamine and serotonin.=

Question 7

Precautions
MAOIs

Answer 7

Overdose carries high risk of fatality; avoid MAOIs if there is a high risk for overdose/suicide.!!!

• Treatment with rizatriptan or sumatriptan—contraindicated (risk of ischaemia is increased as their metabolism is inhibited).
• Angina—MAOIs may reduce pain associated with myocardial ischaemia; use with caution.
• Epilepsy, history of seizures or other risks for reduced seizure threshold, including treatment with drugs that may increase the risk of seizures (table)—MAOIs may increase the risk of seizures (risk less than with TCAs); use low doses and titrate slowly. Note that depression may also increase the risk of seizures.
• Diabetes—MAOIs may reduce blood glucose concentration, possibly affecting control of diabetes; the dose(s) of antidiabetic drugs may need to be reduced.

Question 8

Adverse effects
MAOIs

Answer 8

orthostatic hypotension, sleep disturbances (including insomnia and less commonly hypersomnia), headache, drowsiness, fatigue, loss of libido

Question 9

Counselling
MAOIs

Answer 9

• It is best to take your last dose of the day before 3 pm or you may have trouble sleeping at night.
• Sometimes people who take large amounts of caffeine feel jittery or get headaches when they take this medicine. If this happens, reduce the amount of caffeine you take.
• This medicine may cause drowsiness and increase the effects of alcohol; do not drive or operate machinery if you are affected.
• significant interactions with other medicines (eg hay fever or cold treatments and weight-reducing products). Do not use non-prescription medicines (even nasal sprays) or herbal products, eg St John’s wort, without discussing these with a pharmacist.

Question 10

Practice points
MAOIs

Answer 10

MAOIs are third-line antidepressants, and are usually reserved for use by psychiatrists; they may be useful in atypical depression and psychotic depression; some specialists use MAOIs for post-traumatic stress disorder

Question 11

Drug class and indication

Phenelzine

Answer 11

Antidepressants - MAOIs
Major depression

Question 12

Drug class and indication

Tranylcypromine

Answer 12

Antidepressants - MAOIs
Major depression

Question 13

Drug interactions
MAOIs

Answer 13

MAOIs can cause hypotension; administration with other drugs* that can also reduce BP may result in an additional effect; monitor effect of combinations closely.
MAOIs can cause serotonin toxicity; administration with other drugs that may contribute to serotonin toxicity (table) may increase likelihood; avoid combinations or monitor carefully

Bad / many drug interactions with any drugs such as adrenaline that act on sympathetic nervous sytem

adrenaline + MAOIs
cocaine + MAOIs
dopamine + MAOIs
noradrenaline + MAOIs
pseudoephedrine + MAOIs
SSRIs + MAOIs