Hypotension sceondary to ganlionic blockade.

VASSOPRESSORS USED IN SHOCK-  include-

Inotropic effects -
Isoproternol, Dobutamine, Dopamine, Ephinephrine,

Mixed  effects-
Norephinephrine, Ephedrine, Mephentermine

Pressors effects-
Metaraminol
Methoxamine
Phenylephrine


 

Cerebral haemorrhage and pulmonary oedema,ventricular arrhythmias.

Fear,anxiety, restlessness,tremor,insomnia,confusion,irritabilty  and psychosis.

Nausea, vomiting,  reduced appetite, dysponea, weakness, disturbances of glucose metabolism  sweating, hypersalivation and headache.

 

Hypotension caused by phenothiazines.hypertension.

Special precautions:
Patients on MAOIs.For shock due to loss of blood or fluid,give fluid replacement therapy primarily, CVS disease,hypertension,diabetes,glaucoma.

Hypovalemia- use is not a substitute for replacement ofblood, plasma, fliuds, and electrolytes, which should be restored promptly when loss has occured ie. during or after surgery.

Hemorrhagic shock- use with caution intreatment of shock secondary to hemorrhage .

Hyperthyroidism- increased responsiveness to vasopressor agents may be seen

Hypertensive patients- administer with care to known hypertensives

Warnings-
Use mephentermine with caution in patients with known cardiovascular disease and in chronically  ill patients, since the drugs action on the cardiovsascular system may be profound.

Persistent hypotension during and after surgery usually indicates hypovalemia. Treat by replacing  blood volume.

Pregnancy- use only when clearly needed or when the potential benefits outweigh the potential hazards to the fetus of the nursing infant

 


 

Indications:
Hypotension sceondary to ganlionic blockade.

Dosage:
Can be administered  IM
Dosage of 0.5mg/kg  produces positive response.

Overdosage-
                                          Symptoms                                                                     
Effects of overdosage are an extension of the pharmacological activity of mephentermine
Cardiac contractility, cardiac output, systolic and diastolic blood pressure areusually raised.
Other symptoms include hyperexcitability, prolonged wakefulness, weeping, incoherance, convulsions, flushing, tremor and                 
hallucinations.                                                                           
                       
                                               Treatment

1. Therapy of overdosage is supportive.                                                                           
2. Treat convulsionsor cardiac arrhythmias promptly  if they occur.
3. Because arrhythmias produced by mephentermine  sulfate may be due to excessive beta-adrenergic
   stimulation consider a beta-blocking agent such as  propranolol.



Missed dose-

1. If you miss a dose of this medicine, take it as soon as possible.
2. However, if it is almost time for next dose, skip the missed dose and go back to your regular dosing
 schedule.
3. Do not double doses.  

 

VASSOPRESSORS USED IN SHOCK-  includes-

Inotropic effects -
Isoproternol, Dobutamine, Dopamine, Ephinephrine,

Mixed  effects-
Norephinephrine, Ephedrine, Mephentermine

Pressors effects-
Metaraminol
Methoxamine
Phenylephrine


Pharmacology:
Mephentermine sulphate is a mixed-acting sympathomimetic amine that acts both directly and
indirectly(ie. releases norephinephrine). The increase in blood pressure produced by
mephentermine is probaly due primarily to an increase in cardiac output resulting from enhanced
cardiac contraction; to a lesser degree, an increase in peripheral resistence due to peripheral
vasoconstriction may also contribute to the elevation in blood pressure.

Pharmacokinetics:
The duration of action is prolonged. Pressor response is evident 5 to 15 minutes after IM injection
and has a duration of 1 to 2 hours. The excretion rate of the drug and its metabolites is more rapid
in an acidic urine and is only slightly influenced by urine output.

 

Not applicable

Pregnancy:
Safety for use during , in the nursing  or women of child bearing potential has not been
established. Use only if needed, weihing potential benefits against the potential hazards.