Metoprolol
Is It Right for You?
A complete guide to Metoprolol — what it treats, how it works, dosages, side effects, and when a clinician may prescribe it following an online consultation.
What Is Metoprolol?
Metoprolol is a cardioselective beta-1 adrenergic receptor blocker (beta-blocker) available in two formulations: metoprolol tartrate (immediate-release, IR) and metoprolol succinate (extended-release, XL — marketed as Lopresor and Betaloc ZOK respectively). It is available in tablets of 25 mg, 50 mg, and 100 mg (IR) and 23.75 mg, 47.5 mg, 95 mg, and 190 mg (XL). Metoprolol succinate XL is the preferred formulation for heart failure and once-daily maintenance dosing due to its smoother pharmacokinetic profile and superior evidence base in heart failure (MERIT-HF trial).
Like bisoprolol, metoprolol's cardioselectivity — its preferential affinity for cardiac beta-1 receptors over pulmonary beta-2 receptors — provides a more favourable respiratory side effect profile than non-selective beta-blockers, though it is not completely free of beta-2 effects at higher doses.
Metoprolol is a prescription-only medication in the UK. A clinician must assess your cardiac status, blood pressure, resting heart rate, and respiratory history before prescribing.
What Conditions Is Metoprolol Used For?
Metoprolol is indicated for:
as a second- or third-line antihypertensive, often in combination with other drug classes
reduces myocardial oxygen demand by lowering heart rate and contractility, decreasing the frequency and severity of anginal episodes
metoprolol succinate XL is a cornerstone therapy in chronic heart failure; the MERIT-HF trial demonstrated a 34% reduction in all-cause mortality
used in the acute and post-MI setting to reduce infarct size and improve survival; also used for secondary prevention after MI
slows ventricular response by reducing AV node conduction.
management of paroxysmal SVT and other supraventricular arrhythmias
In heart failure, metoprolol succinate XL must be initiated at a very low dose and up-titrated slowly over weeks to months under clinical supervision. Abrupt discontinuation in any indication — particularly ischaemic heart disease — causes dangerous rebound sympathetic activation, worsening angina, and risk of myocardial infarction.
How Does Metoprolol Work?
Metoprolol is a selective competitive antagonist at beta-1 adrenergic receptors. Its clinical effects are mediated through the following mechanisms:
In hypertension and angina: Metoprolol reduces cardiac output by decreasing both heart rate (negative chronotropy) and myocardial contractility (negative inotropy) through beta-1 receptor blockade in the sinoatrial node and myocardium. It also suppresses renin release from the juxtaglomerular apparatus of the kidney, attenuating the renin-angiotensin-aldosterone system and contributing to sustained blood pressure reduction. In angina, the reduction in heart rate significantly lowers myocardial oxygen demand — the principal driver of ischaemic chest pain on exertion.
In heart failure: Chronic sympathetic nervous system overactivation accelerates pathological cardiac remodelling — hypertrophy, fibrosis, and progressive ventricular dilatation. Metoprolol succinate XL, initiated at low dose and gradually up-titrated, counter-regulates this harmful catecholamine excess at the cardiac level, reversing remodelling, improving ejection fraction over months, and reducing the incidence of sudden cardiac death from ventricular arrhythmias.
In atrial fibrillation: Beta-1 blockade slows conduction through the atrioventricular node, reducing the ventricular rate during AF and improving diastolic filling time, cardiac output, and symptoms of breathlessness and palpitations.
Dosages & Administration
The correct dose depends on the type and severity of infection, age, weight, and kidney function. Always follow your clinician's instructions. The table below is for general reference only.
Administration Tips
IR tablets should be taken with or after food to improve absorption and reduce gastrointestinal side effects. XL tablets should be swallowed whole — do not crush or chew, as this destroys the extended-release mechanism.
Take at the same time(s) each day. XL tablets are designed for once-daily dosing; IR tablets are typically prescribed twice daily.
Never stop metoprolol suddenly. Abrupt withdrawal — particularly in patients with ischaemic heart disease — can precipitate rebound tachycardia, unstable angina, and myocardial infarction. Always taper the dose gradually over at least 1–2 weeks under medical supervision.
Monitor your resting heart rate. If your resting heart rate falls below 50–55 bpm or you experience symptomatic bradycardia (dizziness, near-syncope), contact your clinician promptly.
In heart failure, titrate slowly. Each dose increase should be separated by at least 2 weeks and only undertaken if the previous dose is well tolerated — no evidence of worsening fluid retention, symptomatic hypotension, or significant bradycardia.
Side Effects of Metoprolol
Most side effects are mild and resolve on their own. Serious side effects are rare but require immediate medical attention.
- Fatigue and reduced exercise tolerance --- very common, particularly at initiation; usually improves with time
- Bradycardia (slow heart rate)
- Cold extremities (hands and feet)
- Dizziness and orthostatic hypotension
- Sleep disturbances (vivid dreams, insomnia) --- more common with metoprolol than with bisoprolol due to greater CNS penetration
- Nausea and gastrointestinal discomfort
- Headache
- Severe bradycardia or complete heart block --- heart rate
- Acute heart failure decompensation --- particularly with rapid initiation or dose escalation in heart failure patients; worsening breathlessness, peripheral oedema, orthopnoea
- Bronchospasm --- even cardioselective beta-blockers can trigger bronchospasm in patients with asthma or severe COPD; seek immediate care if new wheeze or chest tightness develops
- Masking of hypoglycaemia --- blunts the tachycardia warning sign of low blood sugar in diabetic patients on insulin or sulfonylureas
- Raynaud's phenomenon exacerbation
Metoprolol is more lipophilic than bisoprolol and penetrates the blood-brain barrier more readily, explaining a higher incidence of vivid dreams, nightmares, and insomnia. If sleep disturbance is troublesome, taking the IR dose in the morning rather than evening, or switching to a less lipophilic beta-blocker such as bisoprolol or atenolol under clinical guidance, may help.
Drug Interactions
Metoprolol may interact with other medications, including verapamil, diltiazem, and class I antiarrhythmics. Always inform your clinician about all medications you are taking.
significantly increase metoprolol plasma levels (metoprolol is extensively metabolised by CYP2D6); risk of bradycardia, hypotension, and toxicity; monitor heart rate closely.
additive AV node slowing; increased risk of bradycardia and heart block; monitor heart rate and digoxin levels.
blunt the antihypertensive effect of metoprolol; avoid regular NSAID use.
no clinically significant interaction.
Important Warnings
Abrupt withdrawal in patients with ischaemic heart disease or heart failure risks rebound sympathetic activation, unstable angina, arrhythmias, and myocardial infarction. Always taper the dose gradually over 1–2 weeks under medical supervision.
Metoprolol is contraindicated in severe asthma. In mild-to-moderate asthma, it must be used only when the cardiovascular benefit clearly justifies the respiratory risk, under specialist supervision, with close monitoring for new or worsening bronchospasm.
Approximately 7–10% of Caucasian patients are CYP2D6 poor metabolisers and achieve plasma metoprolol concentrations 4–5 times higher than average at standard doses. Unusually pronounced bradycardia or side effects at normal doses may indicate this pharmacogenomic phenotype; consider dose reduction or switching to a non-CYP2D6-metabolised beta-blocker such as bisoprolol.
Metoprolol should generally be continued perioperatively; abrupt preoperative discontinuation is harmful. Anaesthetists must be informed of metoprolol therapy before any procedure, as interactions with anaesthetic agents can cause significant bradycardia and hypotension.
Speak to a Clinician About Treatment
Getting advice no longer means sitting in a waiting room. Through The GP Service, you can consult with a licensed clinician in minutes — from home, on your lunch break, or wherever works for you. If treatment is clinically appropriate, your clinician can issue a prescription during the consultation. A consultation does not guarantee a prescription.
The treatment you need, when you need it.
Metoprolol FAQs
Metoprolol tartrate is the immediate-release salt, taken twice or three times daily, with faster peaks and troughs in plasma concentration. Metoprolol succinate is the extended-release formulation, taken once daily, with a smoother and more sustained drug level throughout the 24-hour period. Metoprolol succinate XL is the formulation with proven mortality benefit in heart failure (MERIT-HF) and is the preferred formulation for once-daily maintenance dosing.
Metoprolol's relatively high lipophilicity allows it to cross the blood-brain barrier more readily than other cardioselective beta-blockers like bisoprolol. This CNS penetration is associated with a higher incidence of sleep disturbances including vivid or disturbing dreams, nightmares, and insomnia. Taking doses in the morning rather than at night, or switching to bisoprolol under clinical guidance, can help.
Yes — exercise is encouraged for most patients on metoprolol, particularly those with heart failure or hypertension. However, metoprolol blunts the normal heart rate response to exercise, so your maximum exercise heart rate will be lower than usual. Heart rate-based exercise intensity targets should be adjusted accordingly; your clinician or cardiac rehabilitation team can provide guidance.
Metoprolol can mask the tachycardia that normally warns diabetic patients on insulin or sulfonylureas of a hypoglycaemic episode. Sweating is preserved and remains a useful warning sign. Patients with diabetes requiring tight glucose control should increase the frequency of blood glucose monitoring and be counselled about altered hypoglycaemia symptom awareness.
This depends on your underlying condition. In heart failure and post-myocardial infarction, metoprolol is a lifelong treatment with proven survival benefit — it should not be discontinued without specialist guidance. In hypertension and angina, it is typically a long-term medication, though its continuation is reviewed at each clinical appointment.