The study of the movement of drugs as it moves through the body and involves:
The time interval from when the drug is administered to when its therapeutic effect actually begins.
The study of the drug mechanisms that produce biochemical or physiologic changes in the body (mode of action)
The drug act as an agonist when a drug attracts to a receptor and stimulates it. The drug's ability to initiate a response after binding with a receptor is referred to as intrinsic activity.
Drugs that has an affinity (attraction) for a receptor but doesn't response after binding with a receptor. An antagonist prevents a response from occurring.
Adrenergic blocking drugs AKA sympatholytic drugs
Used to disrupt sympathetic nervous system function
by blocking impulse transmission
at adrenergic neurons or adrenergic receptor sites.
- Action at these sites can be exerted by:
- *interrupting action of adrenergic drugs
- *reducing available norepinephrine
- *preventing the action of cholinergic drugs
Prevents stimulation of the sympathetic nervous system by inhibiting the action of catecholamines at beta-adrenergic receptors.
Used to treat heart problems/ diseases, tremors, glaucoma, migraine, stress,
- *beta1 receptor sites located mainly in the heart
- *beta2 receptor sites located in the bronchi, blood vessels, and uterus.
- *beta1 receptor sites located mainly in the heart
- Penbutolol sulfate
Pharmocokinetic of Beta blockers
- *absorbed rapidly and well from GI
- *protein bound
- *Some beta-adrenergic blockers
- absorbed more completely than others
- *food doesn’t have any effect on
- *peak concentration depends on route
- *distributed widely in body’s
- tissues, highest concentration found in heart, liver, lungs, saliva
- *except for nadolol and atenolol, B1
- metaboized in liver
- *excrete in urine,
- feces, and breastmilk.
Beta blockers side effects
- *peripheral vascular insufficiency
- *atrioventricular block
- *heart failure
- *abdominal discomfort
- *flatulence (gas)
- *fever with sore throat
- *Spasm of the larynx
- *respiratory distress
Beta blocker interactions
- *Cimetidine, digoxin or Ca channel
- blockers increased toxicity
- *NSAID, Antacid, barviturates, Ca
- salts, rifampin can decrease effects.
- *Lidocaine (toxicity)
- *Clonidine with non-seletive B1 can cause severe hypertension
- during clonidine withdrawal.
Beta2 - adrenergic agonists
Used to treat symptoms associated with asthma and COPD. Drugs can be either short acting or long acting.
Short acting Beta 2 agonists
- Used fro ACUTE bronchospasm
- Work in 1-minutes and reach peak effect in 15 minutes
- Routes- inhaled, nebulised, IV, talblet, syrup
Long-acting beta2- adrenergic agonists
- Used to stabilise moderate persistent asthma & activity induced symptoms.
- Used in COPD for symptomatic relief
- Not used in acute exacerbations
Work for 12 hours after each administration
- Eformoterol > Oxis works after 3 minutes
- Lasts 12 hours
- Salmeterol > Serevent works after 30minutes
- Last 12 hours
Pharmacokinetics of beta2 adrenergic agoinst
- minimally absorbed from GI tract
- after inhalation, absorbed over several hours from respiratory tract
- don't cross BBB
- extensively metabolized in liver to inactive compounds
- rapidly excreted in urine and faces
Mood of action of Beta2 adrenergic agonist
Increase levels of cyclic adenosine monophoshate by stimulating the B2A receptors in the smooth muscle resulting in bronchodilation. May lose their selectivity at higher dose which can increase the risk of toxicity
Beta2 agonist side effects
- *paradoxical bronchospasm
- *dry mouth
- Potent anti-inflammatory agent
- work by reducing inflammation; inhibits mast cell rupture, decreases the synthesis of inflammatory mediators, stops new antibody production, suppresses activity of immune cells
- Work slowly over a period of hours and may take 6 to 12 weeks to reduce airway inflammation
- mouth irritation
- upper respiratory infection
- water retention
- impaired wound healing
- Advise the pt to us the lowest possible dosage to reduct the risk of adverse reactons and to maintain control.
- administer doses using a spacer
- rinse out mouth after administration
- not suitable for pregnant women
SSRI's MODE of ACTION
Non-selective re-uptake inhibitor
1 choice antidepressants
Prevent re-uptake of serotonin into pre-synaptic vesicles
Generic name of SSRI's
Pharmocokinetic of SSRI's
- *absorb from GI tract
- with/out food.
- *metabolised in liver
- *excreted in urine
- state levels
- *other serotonin drug
SSRI nursing considerations
- monitor pt mental states
- assess for allergicreaction
- assess vital signs
- avoid alcohol
- Block reuptake of norepinephrine and serotonin. TCA
- intensify the effect of both chemicals by blocking reuptake.
TCA Side effects
- orthostatic hypotension
- anticholinergic effects
- Enhance the action of GABA by binding to specific GABA receptors.
- Only acts to intensified the effect of GABA, doesn’t act as direct GABA agonist
Benzodiazepine side effects
- may cause severe reaction-anaphylaxis
- Warn patient about the possible drugdependency, insomnia during and after withdrawal
- ensure medication is taking only asprescribed to avoid dependency
- avoid use during pregnancy &breastfeeding, can harm foetus
- Block dopamine and serotonin receptors.
- Effects on negative and cognitive symptoms of schizophrenia relate to dopamine release in the prefrontal cortex.
Atypical antipsychotic side effects
- metabolic syndrom
- weight gain
- type2 diabetes
- Cardiac effects
- tachycardia, ECG changes, postural hypotension
- dry mouth
- urinary retention
Used to treat bipolar affective disorder
- May alter Na, K ion transport across cell membrane in nerve, muscle cells
- May alter glutamate uptake and release, blocking binding of serotonin to its receptors and inhibits glycogen.
Lithium side effects
- *Renal toxicity
- *weight gain
- *Kidney function should
- be assessed prior to treatment and once a year thereafter. The risk of renal
- injury can be reduced by keeping the dosage low, and where possible avoiding
- long-term use
Block a variety of receptors including dopamine, acetylcholine, histamine, and norepinephrine
Used to treat mild-moderate pain, osteoarthritis, rheumatoid a. and dysmenorrhea
Act ot reduce the production of prostaglandins that causes inflammation
NSAID generic names
NSAID side effects
- *reduce appetite
Act by depressing pain impulse transmission at spinal cord level by interacting with opioid receptors.
Opioid generic names
- *Onset of action is immediately by
- IV, and rapid by IM or oral
- *Peak occur 1-2 hrs.
- *metabolized in liver
- *excreted in urine
- *can pass placenta
- and breast milk.
- *other opioids
- *alcohol-can increase CNS depression
Opioid side effects
- Used to treat opioid
- overdose, reversal of postoperative opioids effects, relief of opioid-induce
- constipation and management of opioids addiction.
Opioid antagonist mode of action
Drugs that block the effects of opioid agonists.
Opioid antagonist generic names
- Penicillin beta-lactam antibiotic
- Interfere with ability of bacteria to build their cell walls when they are dividing, causing the cell to swell and burst
- sensitive to stomach acid, best absorbed on empty stomach
- space dose throughout the day
- ensure dose is taken until course is finished
- inform the pt the risk of alcohol and antibiotic
Penicillin side effects
- *anaphylactic reactions
- *serum sickness
- *oxacillin may cause liver toxicity
- *abdominal pain
- *sore mouth