No substance of medical value was discovered, however, until 1903 when two German scientists working at Bayer, Emil Fischer and Joseph von Mering, discovered that barbital was very effective in putting dogs to sleep. Barbital was then marketed by Bayer under the trade name Veronal. It is said that Mering proposed this name because the most peaceful place he knew was the Italian city of Verona.It was not until the 1950s that the behavioral disturbances and physical dependence potential of barbiturates became recognized.Barbituric acid itself does not have any direct effect on the central nervous system and chemists have derived over 2,500 compounds from it that possess pharmacologically active qualities. The broad class of barbiturates is further broken down and classified according to speed of onset and duration of action. Ultrashort-acting barbiturates are commonly used for anesthesia because their extremely short duration of action allows for greater control. These properties allow doctors to rapidly put a patient "under" in emergency surgery situations. Doctors can also bring a patient out of anesthesia just as quickly, should complications arise during surgery. The middle two classes of barbiturates are often combined under the title "short/intermediate-acting." These barbiturates are also employed for anesthetic purposes, and are also sometimes prescribed for anxiety or insomnia. This is not a common practice anymore, however, owing to the dangers of long-term use of barbiturates; they have been replaced by the benzodiazepines and Z-drugs such as zolpidem, zaleplon and eszopiclone for sleep.
Combined hepatitis A and B vaccine, is used to provide protection against hepatitis A and hepatitis B. It is given by injection into muscle.It is used in areas where hepatitis A and B are endemic, for travelers, people with hepatitis C or chronic liver disease, and those at high risk of sexually transmitted diseases.The combined vaccine is as safe and protective as if given as separate hepatitis A and B vaccines. It is generally well-tolerated. Common side effects are mild and include redness and pain at the injection site, where a small lump may appear. Feeling faint or tired, or a headache may occur. Other side effects include numbness, tingling, rash, bruising, abnormal bleeding such as from the nose or gums, weak muscle or pain. Severe side effects are rare and include an allergic reaction and seizures.It is widely available. Administration schedule
Routine Twinrix vaccination is administered by intramuscular injection in the deltoid area using a schedule of three separate doses at 0, 1, and 6 months ([minimum intervals: 4 weeks between doses 1 and 2, 5 months between doses 2 and 3]). In some circumstances, an accelerated dosing schedule of 0, 7 and 21 to 30 days followed by a booster at 12 months can be used and was shown to have similar efficacy as the traditional schedule.