Other antidepressants

These antidepressants do not fit into the aforementioned groups and many of them are newer agents.

• Edronax (Reboxetine) - launched in South Africa during 2000. This inhibits noradrenaline reuptake and there is more neurotransmitter available in the synaptic cleft. Generally considered to be an energising antidepressant. It may cause insomnia, dry mouth, vertigo and some sedation initially. Not a good choice if there is a high level of anxiety associated with the depression;
• Efexor (Venlafaxine) - This is a serotonin and nofadrenaline reuptake inhibitor. It is usually an energising drug with side effects similar to SSRI's. There is a newer slow-release preparation which has fewer side effects and seems to be less likely to cause sleep disturbance;
• Lantanon (Mianserin) - classified as a tetracyclic. Affects noradrenaline but via a different mechanism to the tricyclics. This is a sedative antidepressant, which is taken at night - useful if insomnia is a prominent complaint. Also useful if low blood pressure is a problem as it tends not to exacerbate this, unlike the tricyclics. May cause weight gain;
• Molipaxin (Trazodone) - a triazolopyridine antidepressant unrelated to any of the aforementioned antidepressants. It affects the serotonin neurotransmitter system working on pre- and postsynaptic neurones (SSRI's exert their effects on presynaptic neurones only). The main side effect is sedation. Priapism (sustained penile erection) has been reported and may result in irreversible impotence, but this is not a common side effect;
• Remeron (Mirtazapine) - belongs to a new class of antidepressant called NASSA's (noradrenaline and serotonin specific antagonists). Particularly useful if anxiety and insomnia are problems. Side effects include sedation and weight gain.