Part of the opiate group of drugs, pethidine is a painkilling medication. It is also known as meperidine, isonipecaine, and by the brand name Demerol®. A strong painkiller, its uses include relieving pain from operations and childbirth. It can have serious side effects and can be addictive.
Although the drug is synthetic, it has the same mode of action as the natural substance morphine. Pethidine acts on signal receptors in the nervous system. This tricks the body into sensing less pain than it should. It also affects breathing and has a tranquillizing effect.
A patient who suffers from muscle, bone, and abdominal pain can take pethidine for temporary relief. The drug is only recommended for pain that is medium to severe. A doctor can administer the medication before a patient undergoes an operation under a general anesthetic.
During serious operations, it is also used in combination with other anesthetics. When an orthopedic doctor needs to reset broken bones, he or she can administer it along with a sedative drug like diazepam. If a patient experiences more than mild pain after an operation, he or she may also then receive the drug. Childbirth may also be a painful experience, so pethidine is an option during labor. It can have adverse effects on the baby's breathing, so it is only used in situations of severe pain.
The drug is most easily absorbed through injection but it also comes in tablet and syrup form. A typical dose of pethidine for a patient undergoing an operation is 0.25 milligrams per kilogram (mg/kg) of body weight, which can be repeated every 40 minutes to an hour. Laboring women receive 1.0 mg/kg, which is readministered if the pain returns.
Control of pain before and after an operation involves taking up to 150 mg of the drug every four hours for adults and up to 2.0 mg/kg for children. The drug can become addictive, so a patient recovering from an operation, for example, can be restricted to a week's worth of pethidine. If a patient takes the drug for longer periods and then stops, the withdrawal effects can include flu-like symptoms, gastrointestinal problems, and irritability.
Side effects of pethidine include changes in emotional state, gastrointestinal symptoms, and dizziness. Rarely, the drug can cause adverse effects, including allergic reactions, changes in heart rate, and seizures. An overdose can produce blurry eyesight, affect breathing, and even cause coma. Consuming alcohol and other drugs can exacerbate the side effects. People who are older than 65, are drug abusers, or are pregnant or breast-feeding should talk to their doctors before taking pethidine.