Imipramine postsynaptic activity

The first two antidepressants, iproniazid and imipramine, were developed in the same decade. They were shown to reverse the behavioural and neurochemical effects of reserpine in laboratory rodents, by inhibiting the inactivation of these monoamine transmitters (Leonard, 1985). Iproniazid inhibits MAO (monoamine oxidase), an enzyme located in the presynaptic neuronal terminal which breaks down NA, 5-HT and dopamine into physiologically inactive metabolites. Imipramine inhibits the reuptake of NA and 5-HT from the synaptic cleft by their transporters. Therefore, both of these drugs increase the availability of NA and 5-HT for binding to postsynaptic receptors and, therefore, result in enhanced synaptic transmission. Conversely, lithium, the oldest but still most frequently used mood stabiliser (see below), decreases synaptic NA (and possibly 5-HT) activity, by stimulating their reuptake and reducing the availability of precursor chemicals required in the biosynthesis of second messengers. 

Nefazodone is a phenylpiperazine antidepressant, structurally related to trazodone, but it has less alphai-adreno-ceptor antagonist activity and is therefore less sedative. It is a potent 5-HT2 receptor antagonist at postsynaptic receptors, and a weak serotonin reuptake inhibitor. In trials it was more effective than placebo and comparable to imipramine. 

Lavender oil has been demonstrated to exhibit CNS-depressive activities on experimental animals (e.g., mice). Such activities include anticonvulsive effects, inhibition of the spontaneous motor activity, and potentiation of the narcotic effects of chloral hydrate. The hydroalcoholic extract of the flowers of L. stoechas has similar activities. Spike lavender oil has been reported to have spasmolytic effects on smooth muscles of laboratory animals. The mode of antispasmodic action is believed to occur postsynaptically. Lavender has recently been included in aromatherapy preparations that were shown to be effective in dysmenorrhea, in reducing anger, pain and anxiety, and in producing a state of calmness and enhanced well-being. The tincture of L. angustifolia was also found to be effective as an adjuvant to imipramine in the treatment of nuld to moderate depression. Lavender oil has also been reported to have antimicrobial (antibacterial, antifungal) and antiparasitic activities. 

---