Blood or plasma verapamil concentrations are usually in a range of 50–500 μg/L in persons on therapy with the drug, but may rise to 1–4 mg/L in acute overdose patients and are often at levels of 5–10 mg/L in fatal poisonings. Mechanism of action
Verapamils mechanism in all cases is to block voltage-dependent calcium channels. In cardiac pharmacology, calcium channel blockers are considered class-IV antiarrhythmic agents. Since calcium channels are especially concentrated in the sinoatrial and atrioventricular nodes, these agents can be used to decrease impulse conduction through the AV node, thus protecting the ventricles from atrial tachyarrhythmias. Verapamil is also a Kv voltage gated potassium channel blocker.Calcium channels are also present in the smooth muscle lining blood vessels. By relaxing the tone of this smooth muscle, calcium channel blockers dilate the blood vessels. This has led to their use in treating high blood pressure and angina pectoris. The pain of angina is caused by a deficit in oxygen supply to the heart. Calcium channel blockers like verapamil dilate the coronary blood vessels, which increases the supply of blood and oxygen to the heart. They also cause dilatation of systemic peripheral vessels as well, causing a reduction in the workload of the heart. Thereby reducing myocardial oxygen consumption. Cluster headaches
Preventive therapy with verapamil is believed to work because it has an effect on the circadian rhythm and on CGRPs. As CGRP-release is controlled by voltage-gated calcium channels.
Blau syndrome is an autosomal dominant genetic inflammatory disorder which affects the skin, eyes, and joints. It is caused by a mutation in the NOD2 (CARD15) gene. Symptoms usually begin before the age of four, and the disease manifests as early onset cutaneous sarcoidosis, granulomatous arthritis, and uveitis. Presentation
Cause
The elucidation that the gene defect in Blau syndrome (BS) involves the CARD15/NOD2 gene has stimulated many investigators to define how this gene operates as part of the innate immune system. The innate immune system recognizes pathogen-associated molecular patterns (PMAPs), including bacterial polysaccharides such as muramyl dipeptide, via its pattern recognition receptors (PRRs), such as NOD2, to induce signaling pathways that activate cytokine responses and protect the organism. In BS the genetic defect seems to lead to over activation and poor control of the inflammatory response leading to widespread granulomatous inflammation and tissue damage. Diagnosis
Treatment
Treatment has included the usual anti-inflammatory drugs such as adrenal glucocorticoids, anti-metabolites and also biological agents such as anti-TNF and infliximab all with varying degrees of success. History
In 1981, Malleson et al. reported a family that had autosomal dominant synovitis, camptodactyly, and iridocyclitis. One member died of granulomatous arteritis of the heart and aorta. In 1982, Rotenstein reported a family with granulomatous arteritis, rash, iritis, and arthritis transmitted as an autosomal dominant trait over three generations.In 1985, Edward Blau, a pediatrician in Marshfield, Wisconsin, reported a family that over four generations had granulomatous inflammation of the skin, eyes and joints. The condition was transmitted as an autosomal dominant trait.