Pharmacology & Toxicology Flashcards
severe cutaneous adverse reaction allele
HLA-B *5801
type 1 diabetes allelee
HLA-B18
coeliac allele
HLA-DQ2
Multiple sclerosis allele
HLA-DR15
Trastuzumab
Trastuzumab (Herceptin) - monoclonal antibody that acts on the HER2/neu receptor
cardiotoxicity as SE - echo recommended prior to starting treatment
Brimonidine MoA
Brimonidine is an alpha-2-adrenergic agonist aiding in the management of open-angle glaucoma by decreasing aqueous humour production and increasing uveoscleral outflow.
BRIMonidine stops the aqueous humou fom BRIMMING ove/reaching the BRIM
Brinzolamide MoA
Brinzolamide is a carbonic anhydrase inhibitor that decreases aqueous humour production.
ZOLAMIDE = carbonic anhydrase inhibitor
Pilocarpine MoA
a muscarinic agonist which works by contracting the ciliary muscle, in turn opening the trabecular meshwork and thus increasing outflow of aqueous humour.
Used for open angle glaaucoma
Antibiotic class to be avoided in G6PD and what happens
Quinolones e.g. cipoflox
Heamolytic anaeamia with G6PD
managment of lithium toxicity
Management
mild-moderate toxicity may respond to volume resuscitation with normal saline
IV fluids with isotonic saline, until euvolemic, then typically twice maintenance rate
monitor serum sodium closely (every 4 hours with serial lithium concentrations) if there is a concern about lithium-induced nephrogenic diabetes insipidus
haemodialysis may be needed in severe toxicity
sodium bicarbonate is sometimes used but there is limited evidence to support this
by increasing the alkalinity of the urine it promotes lithium excretion
Carbon monoxide poisoning 1st line treatment
Carbon monoxide poisoning: 100% high-flow oxygen is the first-line treatment
Drug-induced impaired glucose tolerance
TASTINg Sugar( impared glucose tolerance)
Thiazides, Antiphychotics, Steroids, T cell in inhibitors(tacrolimus |&| cyclosporin), interferon alpha, nicotinic acid.
Sugar = impared glucose tolerance
buprenorphine MoA in opiod addiction
buprenorphine is a partial agonist of the mu-opioid receptor and an antagonist of the kappa-opioid. It binds to the mu-opioid receptors in the brain but only partially activates them. This partial activation is enough to alleviate cravings and withdrawal symptoms in individuals with opioid dependence. Furthermore, the binding of buprenorphine to the mu-opioid receptor is very strong, or ‘high affinity,’ meaning it can displace other opioids from these receptors and prevent them from exerting their effects. As a kappa-opioid receptor antagonist, buprenorphine may contribute to its ability to reduce symptoms of opioid withdrawal and potentially reduce depressive and dysphoric states.
characteristic of methanol toxicity
metabolic acidosis with a high anion gap; presents with visual disturbances that are characteristic of methanol toxicity
ethylene gycol toxicity management
fomepizole, an inhibitor of alcohol dehydrogenase, is now used first-line in preference to ethanol
P450 inducers:
SCRAP GPS
Smoking
Carbamazepine
Rifampicin
Phenytoin
Griseofulvin
phenobarbitone
St John’s Wort
Flecanide MoA
Flecainide blocks the Nav1.5 sodium channels in the heart
Slows the upstroke of the cardiac action potential by blocking Nav1.5 sodium channels is correct. Flecainide is a Class I antiarrhythmic drug and a potent inhibitor of the cardiac (Nav1.5) sodium channel. This results in slowing of the upstroke of the cardiac action potential thereby ‘reducing excitability’.
COCP Cancer risk
Protective: Ovarian & endometrial
Increased risk: Breast & cervical
Clinical examples of monoclonal antibodies:
infliximab (anti-TNF): used in rheumatoid arthritis and Crohn’s
rituximab (anti-CD20): used in non-Hodgkin’s lymphoma and rheumatoid arthritis
cetuximab (epidermal growth factor receptor antagonist): used in metastatic colorectal cancer and head and neck cancer
trastuzumab (HER2/neu receptor antagonist): used in metastatic breast cancer
alemtuzumab (anti-CD52): used in chronic lymphocytic leukaemia
abciximab (glycoprotein IIb/IIIa receptor antagonist): prevention of ischaemic events in patients undergoing percutaneous coronary interventions
OKT3 (anti-CD3): used to prevent organ rejectio
Aspirin MoA
irreversible COX1 and COX2 inhibitor
Aspirin works by blocking the action of both cyclooxygenase-1 and 2. Cyclooxygenase is responsible for prostaglandin, prostacyclin and thromboxane synthesis. The blocking of thromboxane A2 formation in platelets reduces the ability of platelets to aggregate which has lead to the widespread use of low-dose aspirin in cardiovascular disease.
Adverse effects of quinolones
lower seizure threshold in patients with epilepsy
tendon damage (including rupture) - the risk is increased in patients also taking steroids
cartilage damage has been demonstrated in animal models and for this reason quinolones are generally avoided (but not necessarily contraindicated) in children
lengthens QT interval
Drugs affected by acetylator status
isoniazid
procainamide
hydralazine
dapsone
sulfasalazine
HI-SPeeD
H - hydralazine
I - isoniazid
S- sulfasalazine
P - procainamide
D- dapsone
Drugs exhibiting zero-order kinetics
phenytoin
salicylates (e.g. high-dose aspirin)
heparin
ethanol
t
he zero order drugs illustrate what comes after ‘love at first sight’, ie:
Alcohol
MI (high dose ASA, heparin)
Seizures, and thus need for phenytoin
First-pass metabolism
aspirin
isosorbide dinitrate
glyceryl trinitrate
lignocaine
propranolol
verapamil
isoprenaline
testosterone
hydrocortisone
Cyanide poisoning
Presentation
‘classical’ features: brick-red skin, smell of bitter almonds
acute: hypoxia, hypotension, headache, confusion
chronic: ataxia, peripheral neuropathy, dermatitis
Management
supportive measures: 100% oxygen
definitive: hydroxocobalamin (intravenously), also combination of amyl nitrite (inhaled), sodium nitrite (intravenously), and sodium thiosulfate (intravenously)
Drugs that can cause tinnitus (2)
FUROSEMIDE (not thiazides) and quinine
Benzhexol
Used for managemend of drug induced parkinsonism
Moxonidine
Moxonidine is a centrally acting antihypertensive drug, which works by stimulating imidazoline receptors in the brain. This stimulation results in reduced sympathetic outflow from the central nervous system, leading to decreased vascular resistance and lower blood pressure. It’s mainly used for treating essential hypertension when other treatments are not sufficient or are contraindicated.
Primidone
Used second line for essential tremor
Live attenuated vaccines
You Musn’t Prescribe BCG Incase They RIP Stat= Yellow fever, MMR, Polio, BCG, Influenza, Typhoid, Rotavirus, Shingles’
