1-Docosanol, also known as behenyl alcohol, is a saturated fatty alcohol containing 22 carbon atoms, used traditionally as an emollient, emulsifier, and thickener in cosmetics.In July 2000, docosanol was approved for medical use in the United States as an antiviral agent for reducing the duration of cold sores. It is an over-the-counter medication (OTC). It is sold under the brand name Abreva among others. Side effects
One of the most common side effects that has been reported from docosanol is headache. Headaches caused by the medication tend to be mild and can occur in any region of the head. In clinical trials, headache occurred in 10.4% of people treated with docosanol cream and 10.7% of people treated with placebo.The most serious side effects, although rare, are allergic reactions. Some of the patients experienced the symptoms of allergic reactions, including difficulty breathing, confusion, angioedema (facial swelling), fainting, dizziness, hives or chest pain.Other side effects may include: acne, burning, dryness, itching, rash, redness, acute diarrhea, soreness, swelling. Mechanism of action
Docosanol is thought to act by inhibiting the fusion of the human host cell with the viral envelope of the herpes virus, thus preventing its replication. History
The drug was approved as a cream for oral herpes after clinical trials by the FDA in July 2000. It was shown to shorten the healing by 17.5 hours on average (95% confidence interval: 2 to 22 hours) in a placebo-controlled trial.
Pyridoxine-dependent epilepsy (PDE) is a rare genetic disorder characterized by intractable seizures in the prenatal and neonatal period. The disorder was first recognized in the 1950s, with the first description provided by Hunt et al. in 1954. More recently, pathogenic variants within the ALDH7A1 gene have been identified to cause PDE. Genetics
PDE is inherited in an autosomal recessive manner and is estimated to affect around 1 in 400,000 to 700,000 births, though one study conducted in Germany estimated a prevalence of 1 in 20,000 births. The ALDH7A1 gene encodes for the enzyme antiquitin or α-aminoadipic semialdehyde dehydrogenase, which is involved with the catabolism of lysine. Treatment
Patients with PDE do not respond to anticonvulsant medications, but seizures rapidly cease with therapeutic intravenous doses of vitamin B6 and remission from seizures are often maintained on daily therapeutic doses of vitamin B6. An optimal dose has not yet been established, but doses of 50–100 mg/day or 15–30 mg/kg/day have been proposed. Importantly, excessive doses of vitamin B6 can result in irreversible neurological damage, and therefore several guidelines recommend between 200 mg (neonates) and 500 mg per day as the maximal daily dose.Despite remission of seizure activity with vitamin B6 supplementation, intellectual disability is frequently seen in patients with PDE. Because the affected enzyme antiquitin is involved in the cerebral lysine degradation pathway, lysine restriction as an additional treatment modality has recently been explored. Studies have been published which demonstrate potential for improved biomarkers, development, and behavior in patients treated with lysine restriction in addition to pyridoxine supplementation.