User Tools

Site Tools



Stability & preparation:

  • 10, 40, 160mg dark pink tabs; 1mg/ml 1ml ampoule;
  • Racemic mixture 1:1 ratio - only (-) enantiomer active;


  • Highly lipophilic, almost completely absorbed orally, but 1st pass → only 25% (dose dependant as ? saturable 1st pass) reaches syst.circul.;


  • Vd=4L/kg; Readily enters CNS; 90% bound to plasma proteins;
  • Some taken up in symp.N endings & released upon stimulation;


  • Blocks beta1 & beta2 equally, no intrinsic symp. activity, no alpha-block:
    • decreased renin secretion;
    • bradycardia & negative inotropic effect ⇒ decreased cardiac output;
    • decreased BP if hypertension but full response may take several weeks:
      • (initial increase in peripheral resistance (beta2 block) which later normalises, then falls)
    • suppress exercise-induced tachycardia if therapeutic dose;
    • block catecholamine-induced tremor;
      • decreases spontaneous rate of depolarisation of ectopic pacemakers;
      • decreases conduction in atria & in AV node;
      • increases functional refractory period of AV node;
        • NB. some membrane-stabilising effect (Class Ia) in high [];
      • decreases angina by decreased HR, decreased contractility ⇒ decreased oxygen needs;
      • increased exercise tolerance if exertional angina;
    • beta 2 blockade:
      • bronchospasm
      • blockage of skeletal muscle vasodilatation;
      • adverse lipid profile?;
      • impaired glucose mobilisation & K+ entry into cells;

Metabolism & Excretion:

  • Extensive metabolised → metabolites → urine;
  • T1/2=4hrs, but action lasts long enough for bd dose;

Side effects (see also in C/I):

  • bradycardia & hypotension even at small doses; adverse lipid profile;
  • anorexia, nausea, vomiting, diarrhoea,abdo.pain; dizziness; vivid dreams; insomnia; psych.probs;
  • bronchospasm; cold extremities; rarely skin/blood disorders;
  • may ppt cardiac failure if: AMI, alcoholic cardiomyop., etc;
  • abrupt withdrawal ⇒ inc. angina, AMI, ventricular arrhythmias;

Toxic effects:

  • bradycardia; hypotension; CCF; bronchospasm;

Routes of Administration & Dosage:

  • oral: 40mg bd → 160mg bd (max);
  • IV: 1mg over 1min, repeat 2min prn (max: 10mg or 5mg if GA);


  • unstable diabetes:
    • mask tachycardia response in hypoglycaemia;
    • decr. glucose mobilis. → delay recovery in hypoglyc.
    • (rarely impair insulin release);
  • asthma
    • ⇒ potential life-threatening bronchoconstriction;
    • ⇒ block catecholamine inhib. of mast-cell degranulation;
  • PVD, Raynaud's → vasoconst.→ inc. interm. claudication, esp. smoker;
  • phaeochromocytoma - use alpha-blocker 1st to avoid uncompensated alpha vasoc.
  • athletes
    • decr. exercise tolerance: decr. sk.muscle vasodil.;
    • decr. glucose & FFA mobilisation;
    • decr. cardiac response to exertion;
    • decr. beta induced exertional K shift into sk.muscle cells to buffer the efflux of K from normal exercising muscle cells
  • CCF; or RVF due to pulm.HT; or signif. RVH; or cardiogenic shock;
  • Bradycardia < 50/min; or 2/3 deg. AV block;
  • Myocardial depressant anaesthetics (ether, chloroform, cyclopropane);
  • Prolonged fasting;

Major interactions:

  • verapamil, diltiazem ⇒ AV block & decr. contractility!
  • digoxin ⇒ AV block
  • reserpine/guanethidine ⇒ XS decr. resting symp. tone;
  • Class I antiarrhythmics (eg. disopyramide);
  • clonidine - clonidine should not be stopped until several days after stopping propranolol.
propranolol.txt · Last modified: 2009/02/24 10:05 by

Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki