Meperidine for pain relief

About meperidine

Strong opioids (narcotic analgesics) are medicines used to treat severe pain. Although there are a number of narcotic analgesics, meperidine (also known as pethidine) is the one that has been traditionally used during childbirth, as its effects are shorter-lasting than some of the others. It works on your nervous system and brain to reduce the amount of pain you feel. Meperidine can be taken by mouth as a tablet or liquid medicine, but during childbirth it is more usually given as an injection.

Before having meperidine

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking meperidine it is important that your physician knows:

• If you are pregnant (other than during labor) or breastfeeding.

• If you have liver or kidney problems.

• If you have prostate problems or any difficulties passing urine.

• If you have any breathing problems, such as asthma or chronic obstructive pulmonary disease (COPD).

• If you have been told you have low blood pressure (hypotension).

• If you have any problems with your thyroid or adrenal glands.

• If you have epilepsy.

• If you have a problem with your bile duct.

• If you have been constipated for more than a week or have an inflammatory bowel problem.

• If you have a condition causing muscle weakness, called myasthenia gravis.

• If you have recently had a severe head injury.

• If you have ever been dependent on drugs or alcohol.

• If you have ever had an allergic reaction to a medicine.

• If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.

How meperidine is given

• Before you start the treatment, ask to read the manufacturer's printed information leaflet from inside the pack. It will give you more information about meperidine and will provide you with a full list of the side-effects which you may experience from having it.

• If you have been prescribed meperidine injection, this will be given to you by your physician or nurse. It will be injected under your skin or into a muscle. The injections can be repeated every few hours during labor, if needed. If you are being given meperidine for other types of pain (such as after surgery), the injection can be repeated every three to four hours.

• If you have been prescribed meperidine tablets, take the tablets exactly as your physician has told you to. The usual dose of meperidine is between one and three 50 mg tablets.

• If you have been prescribed meperidine oral liquid medicine, take the liquid exactly as your physician tells you to. Use a measuring cup or oral syringe to measure the correct amount of liquid. The measured dose should be mixed in half a glass of water before swallowing. This is because swallowing undiluted meperidine liquid can numb the mouth.

• When taking meperidine by mouth, the dose should not be repeated more frequently than every three to four hours.

• If you forget to take a dose, take it as soon as you remember and then continue taking your doses every three to four hours from that point. Do not take two doses together to make up for a forgotten dose.

Getting the most from your treatment

• Ask your physician for advice before drinking alcohol. Your physician may recommend that you do not drink alcohol for a while after you have had meperidine because it increases the possibility of side-effects such as feeling dizzy and sleepy.

• If you are a driver, please be aware that meperidine is likely to affect your reactions and ability to drive. It is an offence to drive while your reactions are impaired. Even if your driving ability is not impaired, you are advised to carry with you some evidence that the medicine has been prescribed for you - a prescription form or a patient information leaflet from the pack is generally considered suitable.

• If you are planning a trip abroad and need to take meperidine with you, you are advised to carry a letter with you from your physician to explain why you have been prescribed it. This is because meperidine is classed as a 'controlled drug' and is subject to certain restrictions.

• You will not be given meperidine tablets or liquid for longer than is necessary. This is because repeatedly using meperidine over a period of time can lead to your body becoming dependent on it. When you then stop taking it, it will cause withdrawal symptoms such as restlessness and irritability. If you are concerned about this, discuss it with your physician or pharmacist. This will not become a problem if you are receiving a dose or two of meperidine during labor.

Can meperidine cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with meperidine. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your physician or pharmacist if any of the following continue or become troublesome.

If you experience any other symptoms which you think may be due to this medicine, speak with your physician or pharmacist.

How to store meperidine

• Keep all medicines out of the reach and sight of children.

• Store in a cool, dry place, away from direct heat and light.

Important information about all medicines