Central effects of the calcium antagonist, nifedipine.

Abstract

1 Central effects of the calcium antagonist, nifedipine retard (10, 20 and 40 mg) and nifedipine capsules (10 mg) were studied in 14 healthy male subjects. Two placebos and an active control drug, oxazepam (15 mg), were included. Medication was administered double-blind at 10.00 h. The effects of drugs on performance and subjective feelings were assessed before and from 1.5-2.5 h and 3.5-4.5 h after ingestion, and recordings of the electrical activity of the brain (EEG) and body sway carried out. (15 mg) increased the number of errors (P < 0.01) and reduced accuracy at continuous attention (P < 0.01). 4 Nifedipine (10 mg) reduced total power of the EEG in the frequency range (0.5-30 Hz), and nifedipine (20 mg) increased total alpha power (7.5-13 Hz) (P < 0.05).Oxazepam reduced alpha and increased beta 1 power (13.5-21 Hz). 5 Nifedipine (10 mg) increased (P < 0.05) the amplitude of body sway in the frequency range (1.25-2 Hz), while the dose range 10-40 mg increased 3.25-4 Hz activity.Oxazepam increased the amplitude of 0.05-1 Hz activity. 6 Nifedipine (40 mg) altered mood, with subjects feeling less calm (P < 0.01) while oxazepam reduced alertness (P < 0.05).7 Changes observed with the EEG and mood indicate that nifedipine modifies the activity of the central nervous system, although alertness and performance were not reduced. However, the lack of evidence of sedation with nifedipine suggests that this drug may have advantages over other antihypertensive medication for patients involved in skilled activity.

Effect of combined atenolol and nifedipine administration on psychomotor performance in normal subjects

“…We have also previously demonstrated that this dose of atenolol produces EEG changes consistent with sedation [2]. Nifedipine retard 20 mg used alone produced no significant effects on performance, physiological measurements and subjective awareness, which is also in keeping with our previously published observations [3]. Significant improvements in continuous attention and body sway occurred using the two agents in combination, with no evidence of any adverse central effects.…”

“…This is a well-recognised effect of nifedipine [3], and suggests reflex activation of the sympathetic nervous system due to drug-induced peripheral vasodilatation. The response was abolished in the presence of concomitant/~-adrenoceptor blockade.…”

“…Indeed, drug effects on psychomotor performance may impair the ability to perform work and leisure activities, and lead to poor compliance with treatment. We have previously shown that the fi-adrenoceptor antagonist atenolol and the calcium antagonist nifedipine, conventional firstline agents for the treatment of mild hypertension, each produce small but significant adverse effects on psychomotor performance when used as single agents [1][2][3]. However, approximately half of all hypertensive patients require two or more drugs to control their blood pressure [4], and combination therapy allows relatively small doses of each agent to be used, with the aim of reducing the frequency and severity of adverse effects.…”

Psychomotor performance and antihypertensive treatment.

“…The central effects of acute administration of nifedipine have been studied in 14 healthy male subjects using a range of psychomotor tests [54]. No significant effect was seen on digit symbol substitution test, continuous attention test, letter cancellation, choice reaction time, finger tapping, short-term memory and critical flicker fusion frequency suggesting that alertness and performance were not reduced by nifedipine.…”

The effects of anti‐hypertensive medication on learning and memory.

“…It may be that the drug effects are species-specific, but it also possible that the effects are only seen at critical dose levels or are sensitive to variations in testing procedures. With respect to the cognitive effects of calcium antagonists in non-hypertensive volunteers, McDevitt et al (1991) employed a double-blind comparison of nifedipine and oxazepam with placebo in 14 healthy men, and found no acute effects of a single dose of nifedipine on tests of attention, memory or other psychomotor functions.…”