Generic Name: methamphetamine (meth-am-FET-a-meen)
Methamphetamine has a high potential for abuse. Particular attention should be paid to the possibility of subjects obtaining methamphetamine for non-therapeutic use or distribution to others, and the drug should be prescribed or dispensed sparingly. Misuse of methamphetamine may cause sudden death and serious cardiovascular adverse events .
Medically reviewed by Drugs.com. Last updated on Oct 20, 2020.
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: CNS Stimulant
Chemical Class: Amphetamine (class)
Uses for methamphetamine
Methamphetamine is used to treat attention-deficit hyperactivity disorder (ADHD). It belongs to the group of medicines called central nervous system (CNS) stimulants.
Methamphetamine is also used for weight reduction in obese patients.
Methamphetamine works in the treatment of ADHD by increasing attention and decreasing restlessness in children and adults who are overactive, cannot concentrate for very long, or are easily distracted and impulsive. Methamphetamine is used as part of a total treatment program that also includes social, educational, and psychological treatment.
Methamphetamine is available only with a doctor's prescription. Prescriptions cannot be refilled. A new prescription must be obtained each time you or your child need methamphetamine.
Before using methamphetamine
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For methamphetamine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to methamphetamine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies have not been performed on the relationship of age to the effects of methamphetamine in children with obesity who are younger than 12 years of age, and in children with ADHD who are younger than 6 years of age. Safety and efficacy have not been established.
Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of methamphetamine in the elderly. However, elderly patients are more likely to have age-related kidney, liver, or heart problems, which may require caution and an adjustment in the dose for patients receiving methamphetamine.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking methamphetamine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using methamphetamine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
- Methylene Blue
Using methamphetamine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Abiraterone Acetate
- Calcium Carbonate
- Dihydroxyaluminum Aminoacetate
- Iobenguane I 131
- Magnesium Carbonate
- Morphine Sulfate Liposome
- Opium Alkaloids
- Sodium Bicarbonate
- St John's Wort
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other medical problems
The presence of other medical problems may affect the use of methamphetamine. Make sure you tell your doctor if you have any other medical problems, especially:
- Agitation, severe or
- Anxiety, severe or
- Arteriosclerosis (hardening of the arteries), severe or
- Coronary artery disease or
- Drug abuse, history of or
- Glaucoma or
- Heart attack, recent or
- Heart failure or
- Heart or blood vessel disease (eg, cardiomyopathy) or
- Heart rhythm problem (eg, ventricular arrhythmia) or
- Hypertension (high blood pressure), severe or
- Hyperthyroidism (overactive thyroid) or
- Stroke, history of—Should not be used in patients with these conditions.
- Bipolar disorder (manic-depressive illness), or a family history of or
- Blood vessel problems (eg, Raynaud disease) or
- Depression, or a family history of or
- Hypertension (high blood pressure), mild or
- Psychosis (mental illness), history of or
- Seizures, history of or
- Tourette syndrome, or family history of—Use with caution. May make these conditions worse.
Proper use of methamphetamine
Take methamphetamine exactly as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. If too much is taken, it may become habit-forming. If you feel that the medicine is not working properly after taking it for several weeks, check with your doctor first and do not increase the dose.
Methamphetamine should come with a Medication Guide. Read and follow the instructions carefully. Ask your doctor if you have any questions.
Do not take methamphetamine late in the evening. It may prevent you from falling asleep.
The dose of methamphetamine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of methamphetamine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage form (tablets):
- For ADHD:
- Adults and children 6 years of age and older—At first, 5 milligrams (mg) 1 or 2 times a day. Your doctor may adjust your dose if needed.
- Children younger than 6 years of age—Use and dose must be determined by your doctor.
- For weight loss:
- Adults and children 12 years of age and older—5 milligrams (mg) 30 minutes before each meal.
- Children younger than 12 years of age—Use is not recommended.
- For ADHD:
If you miss a dose of methamphetamine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Precautions while using methamphetamine
It is very important that your doctor check your progress at regular visits to make sure the medicine is working properly and to check for unwanted effects.
You should not use methamphetamine if you have used a drug for depression called an MAO inhibitor (MAOI) such as Eldepryl®, Marplan®, Nardil®, or Parnate® in the past 14 days.
Methamphetamine may cause serious heart or blood vessel problems. This may be more likely to occur in patients who have a family history of heart disease. Check with your doctor right away if you have chest pain, trouble breathing, or fainting while taking methamphetamine.
Tell your doctor right away if you or your family notice any unusual changes in behavior, such as an increase in aggression, hostility, agitation, or irritability. Tell your doctor if you have hallucinations or any unusual thoughts, especially if they are new or getting worse quickly.
If you have been using methamphetamine for a long time and you think you may have become mentally or physically dependent on it, check with your doctor. Some signs of dependence may be:
- A strong desire or need to continue taking the medicine.
- A need to increase the dose to receive the same effects.
- Withdrawal effects after stopping the medicine such as mental depression, nausea or vomiting, stomach cramps or pain, trembling, or unusual tiredness or weakness.
Methamphetamine may cause some people to feel a false sense of wellbeing or to become dizzy, lightheaded, or less alert than they are normally. It may also cause blurred vision or other vision problems. Make sure you know how you react to methamphetamine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or not alert.
Methamphetamine may cause slow growth. If your child is using methamphetamine, the doctor will need to keep track of your child's height and weight.
Methamphetamine may cause Raynaud phenomenon, which is a problem with blood circulation in the fingers or toes. Tell your doctor if you have tingling or pain, a cold feeling, paleness, or skin color changes in the fingers or toes, especially when exposed to cold. Call your doctor right away if you have unexplained sores or ulcers on your fingers or toes.
Check with your doctor right away if you have anxiety, restlessness, a fast heartbeat, fever, sweating, muscle spasms, twitching, nausea, vomiting, diarrhea, or see or hear things that are not there. These may be symptoms of a serious condition called serotonin syndrome. Your risk may be higher if you also take certain other medicines that affect serotonin levels in your body.
Before you have any medical tests, tell the medical doctor in charge that you are taking methamphetamine. The results of some tests may be affected by methamphetamine.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines, herbal or vitamin supplements, and medicine for appetite control, asthma, colds, cough, hayfever, or sinus problems.
Methamphetamine side effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
Incidence not known
- Blurred vision
- chest discomfort or pain
- dark-colored urine
- difficulty breathing
- false or unusual sense of wellbeing
- fast, pounding, or irregular heartbeat or pulse
- muscle cramps or spasms
- muscle pain or stiffness
- pounding in the ears
- shakiness in the legs, arms, hands, or feet
- swelling of the feet or lower legs
- trembling or shaking of the hands or feet
- trouble sleeping
- twitching, twisting, or uncontrolled repetitive movements of the tongue, lips, face, arms, or legs
- uncontrolled vocal outbursts and tics
- unusual tiredness or weakness
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Incidence not known
- Bad, unusual, or unpleasant (after) taste
- change in taste
- decreased interest in sexual intercourse
- dry mouth
- hives or welts, itching, or skin rash
- inability to have or keep an erection
- loss in sexual ability, desire, drive, or performance
- passing of gas
- redness of the skin
- weight loss
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Frequently asked questions
More about methamphetamine
- Side Effects
- During Pregnancy or Breastfeeding
- Dosage Information
- Drug Images
- Drug Interactions
- Support Group
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- 46 Reviews
- Drug class: anorexiants
- FDA Alerts (1)
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