Meperidine: Physiological effects
Last modified: Sunday, 31. May 2009 - 5:19 pm
Other than analgesia, the most common Physiological effects produced by medicinal quantities of meperidine are nausea, vomiting, dry mouth, dizziness, constipation, and itchy skin. These relatively harmless side effects typically disappear in most people after taking the drug for several days, or by reducing the dosage. For most people, higher doses of meperidine are more likely to produce side effects. For those who experience side effects at lower doses, any higher dose is likely to make them more pronounced.
Harmful side effects
The complication of greatest concern is respiratory depression. Opioids affect the area of the brain that controls breathing. A large enough single dose of any opioid, including meperidine, can stop breathing completely, resulting in death. Combining meperidine with another central nervous system depressant, such as alcohol or sedatives, is especially risky. While drowsiness itself is not a harmful side effect, it can be dangerous if someone drives or engages in some other activity that requires them to be alert.
Meperidine presents a higher risk for seizures than other opioids. Seizures induced by meperidine also tend to be resistant to treatment with opioid antagonists. Therefore, people with a history of seizures, and those at increased risk for first occurrence of a seizure (such as someone with head trauma) should avoid meperidine if possible. Other potential neurological side effects include tremors, delirium, and hallucinations. These side effects are uncommon, but serious. Some people may have an allergic reaction to meperidine, and severe cases can involve respiratory arrest; cold, clammy skin; generalized weakness; and unconsciousness or coma.
Patients with kidney or liver disease should exercise caution when using meperidine for any length of time. A by-product of meperidine, normeperidine, is broken down in the liver and excreted by the kidneys. Someone with impaired function of either organ may develop high levels of normeperidine, which can be toxic to the nervous system. Some people, especially the elderly, may have no history of kidney or liver disease, but can have reduced kidney and liver function following surgery. Therefore, if elderly patients must be given meperidine, the safest course may be to limit its length of use as much as possible.
Long-term health effects
Direct, negative effects on long-term health from chronic meperidine use are mostly limited to the slight possibility of central nervous system damage. There are surprisingly few other adverse health effects as far as organ or tissue damage is concerned. This is in contrast to most other abused drugs, with alcohol and tobacco being the obvious examples, and does not match the social stigma associated with opioid drugs.
Compared with other drugs, the relative lack of direct organ or tissue damage from meperidine use is counterbalanced by its high risk for abuse and addiction. High addiction potential in a drug typically means a high risk for long-term use. Long-term use can include either years of continual use or a repeated cycle of use and abstinence. The latter can be especially difficult with meperidine, given the potentially serious withdrawal symptoms associated with abruptly stopping the drug. People with meperidine or other prescription drug addiction are less likely to seek professional help than those who abuse illegal drugs. This may be due to a misperception that addiction to prescription drugs cannot or should not be as serious as illegal drug addiction. Unfortunately, self-treating an addiction usually involves abrupt cessation of the drug, with negative health effects.
The longer and more heavy the abuse, and the more suddenly the drug is ceased, the more serious and painful the withdrawal symptoms will be. Symptoms of withdrawal associated with physical addiction can include restlessness, muscle and bone pain, insomnia, diarrhea, runny nose, chills with goose bumps, and involuntary leg movements. The involuntary leg movements associated with opioid withdrawal are what originally led to the phrase “kicking the habit.” In addition, the goose bumps that often occur during withdrawal originated the use of the phrase “quitting cold turkey,” since the person’s skin resembles that of cold turkey skin. Signs of withdrawal associated with psychological addiction include strong dysphoria (feeling badly) and a nearly uncontrollable craving for the drug.