Beloc

Beloc is the name carried by an imported tablet that contains metoprolol, a beta-blocker. Receptors of the beta-1 type in the heart answer to adrenaline by speeding the pulse and strengthening each beat, and metoprolol occupies those receptors so that the answer is muted. The pulse settles, the muscle needs less oxygen and blood pressure drops. Metoprolol is called cardioselective because it favours the heart over the airways, although the preference weakens as the dose goes up, so asthma and COPD still call for caution.

The UK SmPC for metoprolol tartrate tablets covers raised blood pressure, angina, fast rhythms that arise above the ventricles, protection once the acute phase of a heart attack is over, and migraine prevention. All of these are managed rather than cured. A prescriber will normally expect treatment to continue for as long as it is helping, which can mean years.

Beloc 20 mg and Beloc 40 mg are each offered in 30, 60, 90, 120, 180, 270 or 360 tablets. Because the SmPC works in milligrams per day, the prescriber has to turn its figures into a tablet count. Adults with hypertension start at 100 mg daily and may reach 200 mg. In angina the range is 50 to 100 mg taken two or three times a day, and for rhythm problems 100 to 200 mg daily. After the acute stage of a heart attack the figure is 100 mg twice a day, and for migraine prevention 100 to 200 mg daily. Whatever the reason for treatment, 400 mg in a day is the limit. Reduced kidney function does not require a lower dose, severe liver impairment may, and children are not covered by the SmPC.

Metoprolol tablets are classed as POM in Britain, so a prescription is required. Tablets of 25 mg, 50 mg and 100 mg are licensed there under other names, yet a search of the electronic medicines compendium finds no Beloc tablet, only a Betaloc injection. What is offered on this page is consequently imported, and the listing does not say which salt of metoprolol the tablet contains. Keep the carton and leaflet for a pharmacist or GP to examine.

A heart that is slow or poorly conducting cannot cope with a beta-blocker. The SmPC therefore excludes anyone with second- or third-degree block, sick sinus syndrome or a resting pulse under 50. Systolic pressure below 90 and cardiogenic shock are also barred, along with unstable heart failure, severe peripheral arterial disease, metabolic acidosis and an untreated phaeochromocytoma, and so is severe asthma or COPD. Diabetes needs thought because the tablets can mask the tremor that signals low blood sugar. Psoriasis, an overactive thyroid and Prinzmetal angina call for care too, and the anaesthetist should hear about the tablets before surgery. An abrupt stop is unwise, and the dose is brought down across two weeks or more.

Intravenous verapamil or diltiazem should not be given to a patient on metoprolol except in intensive care. Propafenone and barbiturates are a poor match, and digoxin, other antiarrhythmics and sulfonylurea tablets may need extra monitoring. Tiredness is very common and is generally mild and reversible. A slow pulse, light-headedness on standing, cold fingers and toes, headache, vivid dreams, low mood, an upset stomach and breathlessness are listed as well; blood count changes are very rare. The decision to use Beloc, and the dose, rests with the prescriber.