Pharmacology, Mhu, Mbbs Iv

- Partial seizures and Generalised tonic/clonic.

- Binds voltage gated Na channels=> ⬇propagation APs

- SE: osteopenia, measure active metabolite 10-11 epoxide in serum

• generalised-onset and partial-onset seizures: levetiracetam, topiramate, valproate,

•partial seizures (simple partial, complex partial and secondarily generalized seizures):carbamazepine, gabapentin, phenobarbital, phenytoin, pregabalin (note: these drugs may exacerbate generalized seizures)

• absence seizures: ethosuximide

- Indic in partial, Generalised or mixed seizures.

- Binds voltage gated Na channels=> ⬇propagation APs.

- Cerebral ataxia and osteopenia makes this unpopular with neurologists

CAPTOPRIL:

CoughAngioedemaPotassium excess Taste changesOrthostatic hypotensionPregnancy contraindication/Pressure drop (hypotension)Renal failure/RashIndomethacin inhibitionLeukopenia (rare)

ACE-i (or ARB), diuretic, NSAID

- NSAIDs also blunt the hypotensive effect of ACE-i, diuretics and ARBs

Kidney impairment, mechanical valves

Inc. incretin levels (GLP-1 and GIP)=I glucagon release=> inc insulin secretion, dec gastric emptying =>dec blood glucose

Subcut, acts as exogenous GLP-1

- Purine nucleoside, used IV=>transient complete AV node block

- Useful in diagnosis and tx narrow complex tachy

- Safe in pregnancy. It can also usually be used safely in asthmatics unless they have brittle severe asthma.

- Nausea, vom, drowsiness

- Visual disturbance (dec. acuity, yellow halos, colour changes)

- Hallucinations, confusion, dizziness, neuropathic pain/parasthesia

- Hypotension, palps, syncope, SOB

Electrolytes (acute tox=hyperkal, chronic=hypoK, hypoMg)

Renal function studies

ECG

- Supp care (IV fluids, stop drug, O2)

- Binding resin (cholestyramine) + charcoal

- Correct elect. abnorms

- mgmt. arrythmia

- Positive inotrope

- Vaso and veno constriction

- Enhanced automaticity

- Decreased action potential duration

First line for uncomplicated CAP

all: GI (abdo pain, diarrhoea, N/V), prolonged QT, Vent arrythmias, deafness, increased urea

First line for uncomp CAP

Photosensitivity, rash, anaphylaxis, entercolitis

Eosinophilia, red man syndrome, ototoxicity, renal failure

- eg. mannitol, glycerin

- Freely filtered at kidney=>favours osmotic gradient inside tubular lumen (increases osmolality=>stop water reabsorption

- Inc excretion of Na+, K+, Ca2+, Mg, Cl-, HCO3-, H2PO43- +H20

- Short acting, eliminated quickly through urine

eg. frusemide

- Thick ascending loop of henle

- Stops Na+ reabsorption

- Through the Na+, K+, 2Cl- cotransporter

- Inhibits Cl- resabsorption=>dysnfunction of the whole transported

- Also stops reabsorption of Ca2+ and Mg2+

- Increases H20, Ca2+, Mg2+, Na+, Cl-, K+ excretion

- Dec plasma volume=>renin release

- Eg. hydrochlorothiazide

- Prevent Na+ reabsorption by inhibiting Na+/Cl- cotransporter in DCT (DCT Chlorothiazide)

- Inhibit the excess excretion of Ca2+, but promote, Mg2+ excretion

- Works on a transporter that only reabsorps ~5% Na+=>weak effect

- Inc excretion: Na+, Cl-, K+, H20

- Inc reabsorption of urea in PCT=>don't use in gout

- Decrease reabsorption to Na+

- Stop excretion of K+

- Work on DCT and CD

- Use in conjunction with other diuretics

- Amiolioride

- Work on principle cells of CD and late DCT

- Normal Na+ reabsorped into tubular lumen=>exchanged at K+/Na+ antiporter=>K+ excreted into urine to maintain conc gradient

- These drugs inhibit Na+ absorption into tubular lumen=>therefore H20 loss

- Eg, spironolactone

- Inhibits binding aldosterone to the receptor=>less creation of Na+/K+ antiporters=>prevent excretion of K+, prevent reabsorption of Na+ and H20

- Metabolised by the liver, protein bound

- Work at PCT, stop reabsorption of nabicarb=>Less reabsorption of h20

- Weakest diuresis

Indications: Parkinsonism, drug induced extrapyramidal disorders/dystonia

Pharmacology: exerts anticholinergic and antihistaminic effects, prolongs action of dopamine by inhibiting reuptake and storage

Adverse effects:

*Blurred vision

*Confusion

*Constipation

*Hyperthermia

*Paralytic ileus

*Psychosis

*Tachycardia

*Urinary retention

- Alpha agonist=>reduced sympathetic outflow

- Pre-synaptic and postjunctional alpha-2 adrenoreceptor analgesia, blocks transmission to brain

- May have an effect on prefrontal cortex modulate hyperactivity, distractibility, impulsiveness

- HTN + acute HTN

- Cancer pain

Off-label:

- ADHD

- ETOH withdrawal

- Smoking cessation

- Restless leg syndrome

- Tourette's

- Cyclosporine nephrotoxicity

- Menopausal flushing

- Dysmenorrhoea

- Opioid withdrawal

- Postherpetic neuralgia

- Psychosis

- Pheochromocytoma diagnosis (clonidine supression testing)

- Migraine

- Dry mouth

- Somnolence, fatigue, drowsiness (30%)

- Headache, dizziness

- Anxiety (11%), insomnia, nightmares,

- AV block

- Clindamycin above the diaphragm (eg. aspiration pneumonia, lung abscess)

- Metronidazole below it!