Characterization of ergot and non-ergot serotonin antagonists by prolactin and growth hormone profiles during wakefulness and sleep

Headache, drugs and sleep

Background

Headache and sleep mechanisms share multiple levels of physiological interaction. Pharmacological treatment of headache syndromes may be associated with a broad range of sleep disturbances, either as a direct result of the pharmacology of the drug used, or by unmasking physiological alterations in sleep propensity seen as part of the headache symptom complex.

Purpose

This review summarises known sleep and circadian effects of various drugs commonly used in the management of headache disorders, with particular attention paid to abnormal sleep function emerging as a result of treatment.

Method

Literature searches were performed using MEDLINE, PubMed, and the Cochrane database using search terms and strings relating to generic drug names of commonly used compounds in the treatment of headache and their effect on sleep in humans with review of additional pre-clinical evidence where theoretically appropriate.

Conclusions

Medications used to treat headache disorders may have a considerable impact on sleep physiology. However, greater attention is needed to characterise the direction of the changes of these effects on sleep, particularly to avoid exacerbating detrimental sleep complaints, but also to potentially capitalise on homeostatically useful properties of sleep which may reduce the individual burden of headache disorders on patients.

Pharmacokinetics of a long-acting bromocriptine preparation (Parlodel LA) and its effect on release of prolactin and growth hormone

The pharmacokinetics and endocrine actions of a long-acting form of bromocriptine (Parlodel) were examined in a controlled study in 10 healthy volunteers receiving a single i.m. injection of 50 mg. Six further subjects took bromocriptine 1.25 mg t.i.d. for 3 days p.o. In the subjects given the slow release preparation, the plasma bromocriptine concentrations increased sharply to a maximum of 1.65 mg/l 2 h after injection. This fast release process was followed by slow clearance with a half-life of 16 days. The substance was still detectable in plasma 35 days postinjection. Plasma prolactin (PRL) fell rapidly from a mean of 5.6 ng/ml to reach significantly lower levels at 60 and 120 min. Inhibition was maintained for up to 35 days, when plasma PRL was still significantly below the values recorded at baseline and in the control group. Plasma GH peaked at 3.6 ng/ml at 120 min and subsequently declined slowly to stabilize between 1.4 and 2.2 ng/ml for about 12 h, falling to below the 1 ng/ml limit for the remainder of the study period. In contrast, individuals receiving oral bromocriptine exhibited a significant elevation following the first dose and an equivalent increment after the morning dose on Day 3. Thus, the results show a prolonged inhibitory effect on PRL of this long-acting bromocriptine preparation in parallel with its slow plasma clearance. The stimulant effect on GH secretion is short lived, presumably due to desensitisation of specific receptors.

Neuroendocrinological study of opioid and serotoninergic systems in migraine patients

PRL response to morphine in a group of migraine subjects was studied in the baseline condition and after neuroendocrinological inhibition and stimulation tests. No significant differences were found in comparison with control subjects. This demonstrated the integrity of the opioid system and serotoninergic pathways in migraine subjects.