Phase 1 Pharm

Question 1

Lidocaine

Answer 1

Class 1b antiarrhythmic - used IV

Na+ blockade of ischaemic tissue only
No effect on normal tissue

Reduces phase 0 cardiac AP.

Post MI, may use

Question 2

Flecainide

Answer 2

class 1c antiarrthymic 
IV for AF, SVT, WPW. Very potent decrease in phase 0, restores sinus rhythm but can cause death if struc. heart disease. CNS/GI SEs.

Question 3

Bisoprolol (oral only)

Answer 3

Class ii antiarrthymic

• ADRENALINE STOP: Counteracts sympathetic tachy by reducing slope of pacemaker potential at SAN (hence great for post MI tachycardia)
• AVN SLOTH: Increases refractory period and action potential duration of AVN, protecting ventricles from crazy atrial electrical conduction (hence used in “rate control” of AF).

Indications for use? Tachys, SVTs, AF, reduce o2 demand and prevention of arrhythmias of a failing heart.

Contraindications: ASTHMA – can cause bronchospasm and AV block.

SEs: Hypotension, bronchospasm

Question 4

Amiodarone

Answer 4

Class III antiarrthymic –oral/IV. Used for most arrhythmias. Does a lot more than just K+ blockade (which increases refractory period and action potential duration). It also blocks Na+ (hence decreased phase 0) AND reduces AVN conduction velocity AND slight B blockade.

Problem? Has iodine – so can cause thyroid issues.
Huge half life – has liver and lung SEs.
Can also cause optic neuritis.

Side Effects: Eyes & Thyroid, Liver & Lung

Question 5

Give example of Class IV Antiarrhythmic

Answer 5

Diltiazem

Verapamil

Question 6

Gaviscon

Answer 6

Alginate

Question 7

Ranitidine

Answer 7

H2 receptor antagonists

Question 8

What drugs have narrow therapeutic index?

Answer 8

Guys With Large Dongles Totally Make Perfect Internet Connections

Gentamycin
warfarin
Lithium
Digoxin
Theophylline
Methotrexate
Phenytoin 
Insulin
Cyclosporin

Question 9

Cyp inducers

Answer 9

Craps

Carbamazepine
Rifampicin
bArbituate
Phenytoin 
St Johns wort

Question 10

CYP Inhibitors

Answer 10

Some silly compounds can annoyingly inhibit enzymes grrrr

Sulphonamide
Sodium valproate

Ciprofloxacin
Cimetidine/omeprazole
Antifungals/amiodarone
Isoniazid
Erythromycin/clarithr
Grapefruit juice