me-TOE-proe-lole 
Unlabeled Use:
Contraindicated in:
Use Cautiously in:
CV: BRADYCARDIA, heart block, HF, hypotension, peripheral vasoconstriction.
Derm: rash.
EENT: blurred vision, stuffy nose.
Endo: hyperglycemia, hypoglycemia.
GI: ↑ liver enzymes, constipation, diarrhea, drug-induced hepatitis, dry mouth, flatulence, gastric pain, heartburn, nausea, vomiting.
GU: erectile dysfunction, ↓ libido, urinary frequency.
MS: arthralgia, back pain, joint pain.
Neuro: fatigue, weakness, anxiety, depression, dizziness, drowsiness, insomnia, memory loss, mental status changes, nervousness, nightmares.
Resp: bronchospasm, PULMONARY EDEMA, wheezing.
Misc: drug-induced lupus syndrome.
Drug-Drug:
(Generic available)
When switching from immediate-release to extended-release product, the same total daily dose can be used
Therapeutic Classification: antianginals, antihypertensives
Pharmacologic Classification: beta blockers
Absorption: Well absorbed after oral administration.
Distribution: Crosses the blood-brain barrier, crosses the placenta; small amounts enter breast milk.
Metabolism/Excretion: Mostly metabolized by the liver via the CYP2D6 isoenzyme; the CYP2D6 isoenzyme exhibits genetic polymorphism; 7% of population may be poor metabolizers and may have significantly ↑ metoprolol concentrations and an ↑ risk of adverse effects.
Half-life: 3–7 hr.
(cardiovascular effects)
| ROUTE | ONSET | PEAK | DURATION |
|---|---|---|---|
| PO† | 15 min | unknown | 6–12 hr |
| PO–ER | unknown | 6–12 hr | 24 hr |
| IV | immediate | 20 min | 5–8 hr |
†Maximal effects on BP (chronic therapy) may not occur for 1 wk. Hypotensive effects may persist for up to 4 wk after discontinuation.
NDC Code*
