OXYBRAL SR CAPSULES

Indications

• Cerebrovascular disorders
• Dementia
• Cognitive impairments associated with insufficient cerebral blood flow

Dosage

Children: Refer to the BNF for Children for paediatric dosing information.

Adults: Refer to the BNF for specific adult dosing recommendations.

Mechanism of action

Vincamine's mechanism of action includes vasodilation, particularly in the central nervous system. It has been observed to attenuate long-term potentiation (LTP) and post-tetanic potentiation (PTP) in neuronal pathways, indicating its influence on synaptic transmission. Although the precise pathways remain unclear, vincamine is believed to exert a reserpine-like effect by depleting noradrenaline, leading to its sedative and vasodilating properties. This results in increased cerebral blood flow, especially in regions with inadequate perfusion.

Pharmacodynamics

Vincamine demonstrates sedative properties and influences synaptic activity within the brain. The drug's ability to modulate neurotransmitter systems, particularly through noradrenaline depletion, contributes to its effectiveness in enhancing cerebral blood flow and potentially improving cognitive functions in patients with vascular-related cognitive decline.

Pharmacokinetics

Vincamine is administered intravenously, with studies indicating that a 30 mg dose over 20 minutes can increase cerebral blood flow. The pharmacokinetics regarding its absorption, distribution, metabolism, and excretion are not well-defined in the provided data, requiring further investigation for comprehensive understanding. However, it is known to act relatively quickly in the central nervous system, facilitating its therapeutic effects.

Adverse effects

• Dizziness
• Headache
• Gastrointestinal disturbances
• Hypotension

Precautions

• Use with caution in patients with a history of cardiovascular disease
• Monitor blood pressure during treatment

Pregnancy

There are no adequate and well-controlled studies in pregnant women. Use only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

It is not known whether vincamine is excreted in human milk. Caution should be exercised when administering to nursing mothers.

Storage

Store below 25°C, in a dry place, protected from light.

Formulations

• Tablets
• Injectable solution

Mechanism of action

... At concentrations of 1, 10 and 100 microM, a five-minute perfusion with vincamine did not affect the synaptically-mediated activation of pyramidal neurons evoked by stimulation of the Schaffer-commissural fiber system. The effect of vincamine on the excitability of the pyramidal neurons was investigated by studying its effect on the antidromically-elicited field potential and the input-output relation of Schaffer-commissural fiber input. No effect on either of the two parameters was seen at a concentration of 100 microM of vincamine. Vincamine ... attenuate both the post-tetanic (PTP) and long-term potentiation (LTP) evoked by repetitive stimulation of the Schaffer-commissural fiber system. At a concentration of 100 microM of vincamine, PTP was significantly reduced and LTP was almost completely suppressed. Vincamine's function and therapeutic use as a vasodilating agent, especially at the level of the central nervous system, has been proven after an intravenous administration of 30 mg over a period of 20 minutes in Mongolian gerbils by an increase of cerebral blood flow of approximately 10% and of regional cerebral blood flow in areas with insufficient blood supply by approximately 15%. The mechanism of this vascular action, while not fully clear, seems to be partly due to a reserpine-like noradrenaline depleting effect. Hence, its sedative effects are similar to reserpine