Dictionary

Pharmacology

Drugs, drug classes and the words used to give medications safely.

magnesium hydroxideA magnesium salt taken by mouth as a laxative or an antacid; also called milk of magnesia.

magnesium sulfateA magnesium salt given by IV or IM to raise a low magnesium level or prevent seizures in severe preeclampsia.

magnesium sulfate toxicityHarm from a blood magnesium level that rises too high, usually during magnesium sulfate treatment.

malathionA lotion that kills head lice and their eggs, applied to the hair and scalp.

mannitolAn osmotic diuretic, given by IV, that draws water out of tissues into the blood so the kidneys can remove it.

mcgMicrogram: one millionth of a gram, or one thousandth of a milligram.

mebendazoleA chewable drug that kills intestinal worms such as pinworms, roundworms and hookworms.

mechanism of actionHow a drug works in the body: the exact process by which it produces its effect.

medication administration recordThe part of a client's record that lists every ordered drug, dose, route and time, where nurses record each dose given.

medication errorA preventable mistake at any step of prescribing, preparing, giving or monitoring a medicine, whether or not it causes harm.

medication reconciliationComparing a client's full list of current medicines with new orders at each change in care, to find and fix differences.

medroxyprogesteroneA progestin hormone given as a birth control injection every 3 months, or as tablets for menstrual problems.

melatoninA hormone made by the pineal gland in the brain, mostly at night, that helps control the sleep-wake cycle.

memantineA drug used to ease memory and thinking symptoms in moderate to severe Alzheimer disease.

menotropinsAn injected fertility drug containing the hormones FSH and LH, used to make the ovaries develop eggs.

meperidineA synthetic opioid pain drug, also called pethidine outside the United States.

mercaptopurineAn oral drug that blocks the building of DNA, used for leukemia and to calm the immune system.

mesnaA drug given with some chemotherapy drugs to protect the bladder lining from damage.

metabolismAll the chemical processes in the body's cells that make energy, build tissue and break substances down.

metforminAn oral drug for type 2 diabetes that lowers blood sugar, mainly by reducing the sugar the liver releases.

methadoneA long-acting opioid drug used to treat opioid use disorder and severe pain.

methicillinAn older penicillin-type antibiotic, no longer used in treatment, whose name lives on in MRSA.

methimazoleAn antithyroid drug that lowers the amount of thyroid hormone the thyroid gland makes.

methotrexateA drug that blocks the use of folic acid by cells, used in high doses for cancer and in low weekly doses for autoimmune diseases.

methylergonovineAn ergot drug that makes the uterus contract firmly, given after birth.

methylphenidateA central nervous system stimulant used to treat ADHD and narcolepsy.

methylprednisoloneA corticosteroid drug given by mouth, IV or injection to reduce inflammation and calm the immune system.

metoclopramideA drug that speeds emptying of the stomach and lessens nausea by blocking dopamine.

metoprololA beta blocker that slows the heart rate and lowers blood pressure.

metronidazoleAn antibiotic and antiparasitic drug that treats infections caused by anaerobic bacteria and some protozoa.

mgMilligram: one thousandth of a gram.

MgSO4The chemical shorthand for magnesium sulfate, banned from medication orders by the Joint Commission.

miconazoleAn azole antifungal drug used on the skin, in the vagina or in the mouth for yeast and fungal infections.

midazolamA short-acting benzodiazepine used for sedation before procedures and to stop seizures.

mifepristoneA drug that blocks the hormone progesterone, used with misoprostol to end an early pregnancy, and for some hormone disorders.

mineral oilA lubricant laxative, taken by mouth or as an enema, that coats stool so it passes more easily.

mineralocorticoidA steroid hormone, or a drug that acts like one, that makes the kidneys keep sodium and water and remove potassium.

mirtazapineAn antidepressant taken at bedtime that often causes sleepiness and increased appetite.

misoprostolA prostaglandin drug that protects the stomach lining and also makes the cervix soften and the uterus contract.

misuseUsing something in the wrong way or for the wrong purpose, such as taking a medicine other than as prescribed.

mL/hrMilliliters per hour: the unit for how fast an IV fluid, infusion or tube feeding runs.

MMR vaccineA combination vaccine that protects against measles, mumps and rubella.

modafinilA drug that promotes wakefulness, used for excessive sleepiness from narcolepsy, sleep apnea or shift work.

moderate sedationA drug-induced state of relaxed, lowered awareness in which the client still responds to voice or light touch and breathes on their own.

monoamine oxidase inhibitorA type of antidepressant that blocks an enzyme which breaks down mood chemicals in the brain.

montelukastA tablet that blocks leukotrienes, chemicals that narrow and inflame the airways, used to prevent asthma symptoms and ease allergies.

morphineA strong opioid drug used to relieve moderate to severe pain.

MSAn abbreviation that can stand for morphine sulfate, magnesium sulfate or multiple sclerosis.

MSO4The shorthand for morphine sulfate, banned from medication orders by the Joint Commission.

MTXAn abbreviation for methotrexate; ISMP advises writing the full drug name.