"What are beta blockers?
The class of drugs called beta blockers were given their name because this class of medications counteracts the stimulatory effects of epinephrine (adrenaline) on the so-called beta-adrenergic receptors found"...
BLOCADREN (timolol) is usually well tolerated in properly selected patients. Most adverse effects have been mild and transient.
In a multicenter (12-week) clinical trial comparing timolol maleate and placebo in hypertensive patients, the following adverse reactions were reported spontaneously and considered to be causally related to timolol maleate:
(n = 176)
(n = 168)
|BODY AS A WHOLE|
These data are representative of the incidence of adverse effects that may be observed in properly selected patients treated with BLOCADREN (timolol) , i.e., excluding patients with bronchospastic disease, congestive heart failure or other contraindications to beta blocker therapy.
In patients with migraine the incidence of bradycardia was 5 percent.
In a coronary artery disease population studied in the Norwegian multi-center
trial (see CLINICAL PHARMACOLOGY), the frequency of the principal adverse
reactions and the frequency with which these resulted in discontinuation of
therapy in the timolol and placebo groups were
|Asthenia or Fatigue||5||1||<1||<1|
|Heart Rate <40 beats/minute||5||<1||4||<1|
|AV Block - 2nd or 3rd degree||<1||<1||<1||<1|
|Cold Hands and Feet||8||<1||<1||0|
|Nausea or Digestive Disorders||8||6||1||<1|
|*** When an adverse reaction recurred in
a patient, it is listed only once.
†Only principal reason for withdrawal in each patient is listed. These adverse reactions can also occur in patients treated for hypertension.
The following additional adverse effects have been reported in clinical experience with the drug: Body as a Whole: anaphylaxis, extremity pain, decreased exercise tolerance, weight loss, fever; Cardiovascular: cardiac arrest, cardiac failure, cerebral vascular accident, worsening of angina pectoris, worsening of arterial insufficiency, Raynaud's phenomenon, palpitations, vasodilatation; Digestive: gastrointestinal pain, hepatomegaly, vomiting, diarrhea, dyspepsia; Hematologic: nonthrombocytopenic purpura; Endocrine: hyperglycemia, hypoglycemia; Skin: rash, skin irritation, increased pigmentation, sweating, alopecia; Musculoskeletal: arthralgia; Nervous System: local weakness, increase in signs and symptoms of myasthenia gravis; Psychiatric: depression, nightmares, somnolence, insomnia, nervousness, diminished concentration, hallucinations; Respiratory: cough; Special Senses: visual disturbances, diplopia, ptosis, dry eyes; Urogenital: impotence, urination difficulties.
There have been reports of retroperitoneal fibrosis in patients receiving timolol maleate and in patients receiving other beta-adrenergic blocking agents. A causal relationship between this condition and therapy with beta-adrenergic blocking agents has not been established.
Potential Adverse Effects: In addition, a variety of adverse effects not observed in clinical trials with BLOCADREN (timolol) , but reported with other beta-adrenergic blocking agents, should be considered potential adverse effects of BLOCADREN (timolol) : Nervous System: Reversible mental depression progressing to catatonia; an acute reversible syndrome characterized by disorientation for time and place, short-term memory loss, emotional lability, slightly clouded sensorium, and decreased performance on neuropsychometrics; Cardiovascular: Intensification of AV block (see CONTRAINDICATIONS); Digestive: Mesenteric arterial thrombosis, ischemic colitis; Hematologic: Agranulocytosis, thrombocytopenic purpura; Allergic: Erythematous rash, fever combined with aching and sore throat, laryngospasm with respiratory distress; Miscellaneous: Peyronie's disease.
There have been reports of a syndrome comprising psoriasiform skin rash, conjunctivitis sicca, otitis, and sclerosing serositis attributed to the beta-adrenergic receptor blocking agent, practolol. This syndrome has not been reported with BLOCADREN (timolol) .
Clinical Laboratory Test Findings: Clinically important changes in standard laboratory parameters were rarely associated with the administration of BLOCADREN (timolol) . Slight increases in blood urea nitrogen, serum potassium, uric acid, and triglycerides, and slight decreases in hemoglobin, hematocrit and HDL cholesterol occurred, but were not progressive or associated with clinical manifestations. Increases in liver function tests have been reported.
Read the Blocadren (timolol) Side Effects Center for a complete guide to possible side effects
Catecholamine-depleting drugs: Close observation of the patient is recommended when BLOCADREN (timolol) is administered to patients receiving catecholamine-depleting drugs such as reserpine, because of possible additive effects and the production of hypotension and/or marked bradycardia, which may produce vertigo, syncope, or postural hypotension.
Non-steroidal anti-inflammatory drugs: Blunting of the antihypertensive effect of beta-adrenoceptor blocking agents by non-steroidal anti-inflammatory drugs has been reported. When using these agents concomitantly, patients should be observed carefully to confirm that the desired therapeutic effect has been obtained.
Calcium antagonists: Literature reports suggest that oral calcium antagonists may be used in combination with beta-adrenergic blocking agents when heart function is normal, but should be avoided in patients with impaired cardiac function. Hypotension, AV conduction disturbances, and left ventricular failure have been reported in some patients receiving beta-adrenergic blocking agents when an oral calcium antagonist was added to the treatment regimen. Hypotension was more likely to occur if the calcium antagonist were a dihydropyridine derivative, e.g., nifedipine, while left ventricular failure and AV conduction disturbances were more likely to occur with either verapamil or diltiazem.
Intravenous calcium antagonists should be used with caution in patients receiving beta-adrenergic blocking agents.
Digitalis and either diltiazem or verapamil: The concomitant use of beta-adrenergic blocking agents with digitalis and either diltiazem or verapamil may have additive effects in prolonging AV conduction time.
Quinidine: Potentiated systemic beta-blockade (e.g., decreased heart rate) has been reported during combined treatment with quinidine and timolol, possibly because quinidine inhibits the metabolism of timolol via the P-450 enzyme, CYP2D6.
Clonidine: Beta adrenergic blocking agents may exacerbate the rebound hypertension which can follow the withdrawal of clonidine. If the two drugs are coadministered, the beta adrenergic blocking agent should be withdrawn several days before the gradual withdrawal of clonidine. If replacing clonidine by beta-blocker therapy, the introduction of beta adrenergic blocking agents should be delayed for several days after clonidine administration has stopped.
Risk from Anaphylactic Reaction: While taking beta-blockers, patients with a history of atopy or a history of severe anaphylactic reaction to a variety of allergens may be more reactive to repeated accidental, diagnostic, or therapeutic challenge with such allergens. Such patients may be unresponsive to the usual doses of epinephrine used to treat anaphylactic reactions.
Read the Blocadren Drug Interactions Center for a complete guide to possible interactions
Last reviewed on RxList: 12/9/2008
This monograph has been modified to include the generic and brand name in many instances.
Additional Blocadren Information
Blocadren - User Reviews
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