Reversible Monoamine Oxidase Inhibitor (RIMA) Antidepressants

Types

There are a number of different RIMA antidepressants.

Brand name Chemical name
Auririx Moclobemide

How RIMAs work

Reversible Monoamine Oxidase Inhibitor Antidepressants (RIMAs) work by reducing the activity of monoamine oxidase which is a chemical found throughout the body. Monoamine oxidase breaks down noradrenaline (also called norepinephrine) and serotonin and other chemicals made and used by the body and brain. These chemicals are important in emotions and depression. RIMAs increase the amount of noradrenaline and serotonin in the brain and can work as antidepressants.

Side effects

Common side effects include:

  • Sleep disturbance at night
  • Agitation
  • Dizziness on standing
  • Sleepiness during the day (care is needed with driving)
  • Dry mouth
  • Tremor (slight shake of muscles of arms and hands)

Effect on weight and sleep:

  • There is little effect on weight.
  • Difficulty getting to sleep and broken sleep
  • Intense daytime sleepiness

Dangers

RIMAs may cause lowered blood pressure especially on standing. This may cause fainting.

Overdosage

An overdose of an RIMAs causes restlessness but the danger is slight. However, an overdose of RIMAs may be dangerous in combination with overdose of other medications..

Interactions with other drugs

  • SSRI antidepressants (Prozac, Zoloft, Aropax, Cipramil, Luvox) may cause 'serotonergic syndrome' of fever, muscle shakes and seizures.
  • Narcotic analgesics (morphine etc) may increase effect
  • The effect of stimulant drugs such as Ritalin and Dexamphetamine (used to treat Attention Deficit
  • Hyperactivity Disorder (ADHD)) may be increased. (Some cold cures and hay fever and sinus medications bought over the counter can have stimulant effects).
  • Selegiline (Eldepryl, Selgine used for Parkinson's disease) should not be used with RIMAs

Effect with food

There are no significant interactions with foods.

When SSRIs must not be taken

SRIMAs must not be taken at the same time as non-reversible monoamine oxidase inhibitors (Parnate or Nardil).

Use in Pregnancy and Breast Feeding

RIMAs have not been shown to be harmful to the foetus in pregnancy. However, there have been few studies in humans. RIMAs appear in breast milk. Very small quantities of RIMAs appear in breast milk. There have been no studies of the safety of this for babies. The manufacturers recommend caution in breast feeding but do not recommend that breast feeding must be stopped.

Withdrawal effects

Antidepressants are not addictive. However, some people experience slight withdrawal effects on stopping RIMAs.

Dosage and time of dose

The starting dose is usually 150mgm twice daily (300 mg daily). This is gradually increased to 600mgm or sometimes 900 mgm daily. Even higher doses have been used in very special circumstances.

Morning and daytime dosage is most common as many people find that RIMAs disturb sleep. The time of day the dose is taken does not change its effectiveness against depression.

If a dose is missed take it as soon as possible. If a morning dose is missed it can be taken later in the morning. If an afternoon dose is missed, do not take it

Name Chemical name Common dose* Most common time of dose
Aurorix Moclobemide 150mgm - 600mgm Morning and afternoon
* with careful observation these doses may be considerably increased by your doctor

How long do you need to be on a medication?

You will need to take the antidepressant for at least 6 to 9 months after your symptoms disappear. Stopping your antidepressant too early increases your chances of suffering a recurrence of depression.

Last reviewed and updated: 8 February 2006