Meperidine - Effects on the Body

Effects on the Body

Physical pain occurs when illness or injury causes pain signals to be transmitted to the brain through nerve cells in the body. The pain-relieving effect of an opioid like meperidine is produced when

Some schools and communities seek to prevent young people from turning to drugs, alcohol, and tobacco. They offer life skills training programs so students can build self-esteem and confidence, set goals, and learn how to cope with peer pressur
Some schools and communities seek to prevent young people from turning to drugs, alcohol, and tobacco. They offer life skills training programs so students can build self-esteem and confidence, set goals, and learn how to cope with peer pressure and avoid addiction. © Mark Peterson/Corbis.

the drug blocks these signals by interacting with proteins called opioid receptors that exist on the surface of nerve cells. The chemical relationship is something like keys and locks. The narcotic drug fits into the receptor proteins and opens a pathway for chemical changes that reduce the ability of the nerve cell to transmit pain signals. When this happens, fewer pain signals are received by the brain, which means that the person taking the drug feels less pain.

If opioids are used when one is not in pain, the chemical changes in the nerve cells and the brain can produce feelings of euphoria, or a state of extreme happiness and well-being. When this occurs over a period of time, the nerve cells become tolerant of the effect, which means that more of the chemical substance is needed to produce the same sensation. Over the course of time, the body also becomes addicted to the basic chemical action of the drug. Thus, if the drug is discontinued, the user experiences unpleasant physical symptoms of drug withdrawalThe process of gradually cutting back on the amount of a drug being taken until it is discontinued entirely; also the accompanying physiological effects of terminating use of an addictive drug..

Addiction Problems

Opioids can also cause psychological addiction or dependence. This is present when a person craves a drug and feels a compulsive need to take it, no matter what the consequences may be. This is what drives many people to commit crimes ranging from fraud to robbery in order to acquire the prescription drugs on which they are dependent. They become psychologically addicted to the emotional sensations that accompany the physical effects of the drug. Psychological addiction generally does not occur when people use prescription opioids for long-term, chronic pain. However, it is possible for legitimate use to turn into abuse in individuals who have developed physical dependence when their doctors decide that prescription narcotics are no longer appropriate as treatment. This is what has happened to many people who have become hooked on these painkilling drugs that were prescribed for them for long-term use after surgery or an injury of some kind.

Meperidine is generally used to treat acute pain, so medical use does not usually lead to either physical dependence or tolerance. Prescription users of meperidine do not need more and more of the drug to get the needed level of pain relief. However, when the drug is used specifically to get high, users typically develop both physical tolerance and addiction and psychological addiction. This means they not only crave the drug and physically need more of the drug just to get high, they also need to keep taking the drug to avoid the discomfort of chemical withdrawal.

When a person who is addicted to the physical aspects of a drug suddenly stops taking that drug, withdrawal symptoms occur. Opioid withdrawal is not life threatening, as is sometimes the case with the physical withdrawal from some heavily used substances, such as alcohol and barbiturates. It is unpleasant, however. Short-term withdrawal symptoms include anxiety, yawning, sweating, abdominal cramps and diarrhea, chills and "goose bumps," and a runny nose. Symptoms begin to appear about four or five hours after the last dose. They are at their most intense between thirty-six and seventy-two hours later, and are generally over within a week or ten days. Complete detoxification and recovery from physical addiction can take six months or more.

Side Effects of Meperidine Use

Even when meperidine and other opioids are taken under medical supervision, side effects can occur. Opioids relieve pain by temporarily altering the function of nerve cells. In addition to reducing one's pain, this may also cause mental confusion, drowsiness, dizziness and/or nausea, constipation, sweating, low blood pressure, or a slow heartbeat. More serious effects include convulsions and respiratory distress. These most frequently occur if the drug's dosage is too high, or if a patient combines meperidine with alcohol or other drugs.

Patients with kidney or liver disease may be at risk of nervous system damage if they use meperidine for a significant length of time. A by-product of meperidine called 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 (poisonous) to the nervous system.

People with a history of seizures, or those who have experienced recent head trauma, which puts them at risk of a first seizure, should avoid the use of meperidine. This is because meperidine presents a higher risk for seizures than other opioids. Other serious, but rare, neurological side effects include delirium, hallucinations, and tremors. Allergic reactions to meperidine are unusual, but severe cases can cause symptoms such as cold, clammy skin, generalized weakness, respiratory arrest, and unconsciousness or coma.