Interacting drugs- summary

+ Isoproterenol

 Bretylium                                                                                                                               bretylium potentiates the action of vasopressors on adrenergic receptors, possibly resulting in arrhythmias

Guanethidine-                                                                                                              guanethidine may increase the pressor response of the direct-acting vasopressors, possibly resulting in severe hypertension

Halogenated hydrocarbons anesthetics-                                                                                    halogenated hydrocarbon anesthetics may sensitise the myocardium to the effects of catecholamines. Use of vasopressors  may lead to serious arrhythmias, use with caution.

Oxytocic drugs-                                                                                                                      in obsteritics, if vasopressor drugs are used either to correct hypotension or added to the local anesthetic solution, some oxytocic drugs may cause severe persistent hypertension

Tricyclic antidepres-                                                                                                               the pressor response of the direct-acting vasopressors may be potentiated by these agents; use with caution.

Hypovalemic and septic shock, heart block and Adams- Stokes attack

VASSOPRESSORS USED IN SHOCK- includes- Inotropic effects - Isoproternol, Dobutamine, Dopamine, Ephinephrine, Mixed effects- Norephinephrine, Ephedrine, Mephentermine Pressors effects- Metaraminol Methoxamine Phenylephrine

Cardiovascular- Tachycardia, palpitations, hypertension, ventricular arrhythmias, tachyarrhythmias, precordial distress, angina.

CNS- Flushing of skin,sweating, mild tremors, nervousness, headache, dizziness, weakness.

GI- Nausea, vomiting.

Tachyarrhythmias, tachcardia or heart block caused by digitalis intoxification, ventricular arrhythmias which require inotropic therapy, angina pectoris.

Special precautions:

Hypovalemia- should be corrected by suitable volume expanders before treatment with iosproterenol.

Cardiovascular disorders- use with caution in coronary artery disease, coronary insufficiency, diabetes or hypothyroidism and in patients sensitive to sympathomimetic amines

Cardiac effects- if heart rate exceeds 110 beats/min, advisable to decrease infusion rate or discontinue temporarily. Detremination of cardiac output and circulation time and also be helpful.

Sulfite sensitivity- some of these products contain sulfites that may cause allergic type reactions including anaphylactic symptoms and life threatening or less severe asthmatic episodes in certain susceptible individuals.

Warnings

Cardiogenic shock- isoproterenol inejction by increasing myocardial oxygen requirements while decreasing effective coronary perfusion may have a deleterious effect on the injured or failing heart .

Its use an the initial agent in treating cardiogenic shock following myocardial infarction is discouraged

Heart block- Isoproternol has pardoxically worsened heart block or precipated

Adams- Stokes attacks during normal sinus rhythm or transcient heart block.

Pregnancy- use only when needed and when benefits outweigh potentail hazards to the fetus.

Lactation- excercise caution when administering to a nursing woman.

Indications: Hypovalemic and septic shock, heart block and Adams- Stokes attacks

Dosage: American Heart Asson. recommends an initial infusion rate of 0.1mcg/kg/min with usual range being 0.1mcg/kg/min to 1mcg/kg/min.

Overdosage- Symptoms Excessive doses in animals or man may result in cardiac enlaegement and local myocarditis. Cases of accidental ovedosage are evidenced by tachycardia or other arrhythmias,palpitatons, angina, hypotension,or hypertension

Treatment

1. Reduce rate of administration or discontinue isoproternol until patients condition satbilizes.

2. Monitor blood pressure,pulse, respiration and EKF

Missed dose-

1. If you are using this medicine regularly and you miss a dose, use it as soonas possible.

2. Then use the remaining dose for that day at regularly spaced intervals.

3. Do not double doses.

1. Do not exceed the recommended dosage, excessive use may lead to adverse effect or loss of efectiveness.

2. Do not stop or adjust the dose.

3. Do not change brands without consulting the physician or the pharmacist.

4. If more than one inhaltion is necessary,wait for at least one full minute between inhalitions (administer the second inhalation at 3 to 5 minutes for isoproternol and epinephrine, 2 minutes for metoproternol ).

5. Notify physician of failure to respond to usual dosage or of dizziness or chest pain.

6. Isopreternol may cause the patients saliva to turn pinkish-red.

  Pharmacology:

Isopreterenol has beta2 adrenergic receptoractivity. Primary actions are on the beta receptors of the heart and smooth muscle of the bronchi, skeletal muscle and vasculature and alimentary tract.

Pharmacokinetics:

Onset of activity is approximately 30 minutes after SL admin and immediate after IV admin. Duration is brief, 1 to 2 hours aand less than 1 hour respy,

Pregnancy: Use only when needed.

Lactation: Excercise caution when administering to a nursing woman.