TABLE 8.

Analgesic antidepressants

				Neurotransmitter profile		Most common side effects (%)
Drug	Common trade name	Therapeutic range for pain (mg/24 h)	Half-life (h)	NA	5-HT	Sedation	Orthostatic hypotension	Weight gain	Dry mouth	Constipation	GI distress, nausea, diarrhea
Tricyclics
Amitriptyline	Elavil†	10–150*	10–46	+++	+++	>30	>10	>30	>30	>10	>2
Doxepin	Sinequan‡	10–150*	8–36	+++	++	>30	>10	>10	>30	>10	<2
Trimipramine	Surmontil§	10–150*	7–30	++	+	>30	>10	>10	>10	>10	<2
Imipramine	Tofranil¶	10–150*	4–34	+++	+++	>10	>30	>10	>30	>10	>10
Clomipramine	Anafranil**	10–150*	17–37	+++	++++	>2	>10	>10	>30	>10	>10
Desipramine	Norpramin§	10–150*	12–76	+++++	++	>2	>2	>2	>10	>2	>2
Nortriptyline	Aventyl††	10–100*	13–88	++++	++	>2	>2	>2	>10	>10	<2
Serotonin/noradrenaline reuptake inhibitors
Venlafaxine	Effexor‡‡	37.5–225	3–7 (parent) 9–13 (metabolite)	++	++++	>10	>10	<2	>10	>10	>30
Duloxetine	Cymbalta§§	60–120	10	++++	+++++	>10	<10	<2	>10	>10	>10

^*The therapeutic range for depression is up to 200 mg/24 h for nortriptyline and to 300 mg/24 h for the remaining tricyclic antidepressants; generally, these doses are not required for an analgesic effect and the usual dose will consist of 75 mg/24 h or less;

^†1560678 Ontario Inc, Canada;

^‡ERFA Canada Inc;

^§Aventis Pharma Inc, Canada;

^¶Novartis Pharmaceuticals, Canada;

^**Oryx Pharmaceuticals Inc, Canada;

^††Pharmel Inc, Canada;

^‡‡Wyeth Canada;

^§§Lilly, USA. 5-HT 5-Hydroxytryptamine; GI Gastrointestinal; NA Noradrenaline. Adapted from reference 286