captopril

competitive inhibitor of ace

afterload reduction, myocardial remodeling in CCF

reduce SVR, decrease BP, no increase in HR

Adverse effect:

• reduced renal blood flow
• transient hypotension with first dose
• hyperkalaemia (reduced aldosterone)
• angioedema (2-3%), agranulocytosis, thrombocytopenia
• cough

well absorbed - bioavailibility 65%

 

 

Enalopril

prodrug via hepatic metabolism

hydrolysed in liver and kidney to active metabolite

elimination half life - 4-8 hrs

duration of effect 20hrs

 

 

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GTN

• More potent venodilator
• NO donor: GTN + cysteine =  nitrosothiol compound = NO release
• Adsorbed onto PVC plastic

Effects

• Preload reduction
• Coronary circulation, pumonary circulation
• Uterine muscle relaxation

 

Adverse effects:

• Met Hb in neonates
• Headaches, hypotension
• Tolerance - depletion of SH donor. Give N-acetyl cysteine or nitrate free period to allow recovery of SH donor

 

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N-acetyl cysteine can be used to loosen secretion

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Verapamil and diltiazem acts on the inner gate of calcium channel

Nifedipine acts on the outer gate of calcium channel

 

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Magnesium, calcium role in antiarrhythmia

 

Magnesium -

Vasodilation

Used for ventricular arrhythmia

Blocks NMDA receptor

Inhibits release of Ach at NMJ (Calcium enhance release)

Inhibits release of NE and other neurotransmitters

Used in bone formation