Pharmacology Flashcards
Mechanism of action of ipratropium bromide
Non-selective muscarinic antagonist (M1-M5). M3-muscarinic ACh receptors –> opposing bronchoconstriction and mucus production.
Side effects muscarinic antagonists eg atropine
Dry eyes, constipation, headaches, fatigue
Mechanisms of action of Montelukast
Blocks action of Leukotriene D4 in lung –> relaxation of SM, decreased inflammation (reduced released of alveolar macrophages, eosinophils, mast cells).
Side effects of montelukast
Sleep disturbance
Increased thirst
Steroid mechanism of action
- Reduced production of inflammatory mediators eg prostoglandins, leukotrienes
- Increased anti-inflammatory molecules
- Vasoconstriction
Side effects of long term steroids
Weight gain, central adiposity
Muscle weakness
HTN
Striae
OP
Glaucoma, cataracts
Significant reduction in growth velocity
Medications that can cause hearing loss
Gentamicin
Chemo eg cisplatin
Loop diuretics can potentiate effects
Side effects of gentamicin
Nephrotoxicity
Hearing impairment
Colitis
Neurotoxicity
Side effects of vancomycin
Agranulocytosis
Hearing loss
Pseudomembraneous colitis
Red man syndrome (rapid administration).
OD: interstitial nephritis.
Side effects of methotrexate
BM suppression
Nausea
Abnormal LFTs
Avoid NSAIDs - renal excretion
Mucositis (disturbed folic acid)
Pulmonary fibrosis
Side effects sodium valproate
Thrombocytopenia
Methylphenidate - uses and SE
Used for ADHD
SE: weight loss, aggression, alopecia, GI disturbance, sleep disturbance
Mechanism of action atomoxetine
Alters neuroendocrine env. of brain over weeks - mainly norepinephrine pathway
ADHD - esp tics / concern family diversion meds
Uses and Side effects of atomoxetine
Used in ADHD - esp tics / concern family diversion meds
Suicidal ideation
Self-harm
Liver damage
Side effects of SSRIs
Anxiety
Nausea / diarrhoea
Dizziness
Dry mouth
Blurred vision
Seratonin syndrome - confusion, sweating
Lithium Uses and SE
Used in Bipolar
Toxic to thyroid and kidneys
Side effects of atypical antipsychotics
Weight gain
Hyperlipidaemia / DM
QTc prolongation
Lactation
Medications that can cause low magnesium
Omeprazole
Loop diuretics
Aminoglycosides
May present with Sx of hypocalcaemia
Nifedipine SE
Gum hypertrophy
Side effects of PO retinoids eg isotretanoin
- Teratogenic
- Dry skin
- Photosensitivity
- Depression / suicidal ideation
- IBD
Mechanism of action of Asparaginase
Chemo agent. ACTS ON G1.
Enzyme. Degrades AA L-asparagine –> tumour cells unable to produce more.
Chemotherapy agents that act on S phase of cell cycle
Block synthesis of normal nucleic acids for DNA synthesis.
Methotrexate
Cytarabine
Mercaptopurine
Mechanism of action of Etoposide
Chemo. ACTS ON G2. Inhibits topoisomerase type 2 –> prevents DNA repair and entry into M
Mechanism of Vincristine
Chemo. Acts on Mitosis. Blocks microtubule assembly –> prevents formation of mitotic spindle needed from Ch division
Eg in Hodgkin’s lymphoma
SE: peripheral neuropathy
Mechanism of cyclophosphamide / Ifosphamide
Chemo. Not specific phase.
Cross link DNA strands –> DNA can’t replicate.
SE: Haemorrhagic cystitis
Mechanism of antibiotics as chemo agents
Doxorubicin - Binds to DNA and prevents transcription. Used in Ewing’s sarcoma, ALL, AML, lymphoma. SE: Cardiotoxic, dilates.
Actinomycin - Free radical production –> apoptosis
Mechanism of cisplatin / carboplatin
Chemo. No specific phase.
Bind to DNA, prevent replication and transcription –> apoptosis.
Rituximab mechanism of action
Attach to CD20 (B cells) –> cell death
Used eg in lymphoma, vasculitis, JIA
Mechanism of action blinatumomab
CD19 on B lymphocytes
Used in leukaemia
Mechanism of action Omalizumab
IgE
Tx used in asthma
Mechanism of action palivizumab
Inhibits RSV fusion protein
Mechanism of Tocilizumab
Down-regulation of IL-6
Used in RA
Mechanism of action Infliximab
Inhibits TNF-alpha (cell signalling)
Indications: RA, IBD, Ank spond
Mechanism of action Ciclosporin / tacrolimus
Inhibits activation of T lymphocytes = Calcineurin inhibitor
Mechanism of action and side effects of Lamotrigine
Sodium channel inhibition, some calcium channel inhibition
SE: Visual changes, rash –> SJS
Mechanism of action and side effects of Carbamazepine
Sodium channel inhibition
SE: GI upset, diplopia, blurred vision, SJS
Mechanism of action and side effects of Phenytoin
Sodium channel inhibition
SE: Gum hypertrophy, poor coordination and tremors, slurred speech
Mechanism of action and side effects of Ethosuxamide
Calcium channel inhibition (T-type)
SE: sleep disturbance, GI upset
Mechanism of action and side effects of Phenobarbitone
GABA receptor agonist
SE: Sedation
Mechanism of action and side effects of Vigabatrin
Inhibits GABA transaminase –> increased GABA
SE: Weight gain, hyperactivity, visual field loss
Mechanism of action and side effects of Benzodiazepines
Increased GABA receptor agonist
SE: Resp depression, tolerance / withdrawal (insomnia, headache, sweating, palpitations, anxiety)
Mechanism of action and side effects of Sodium valproate
Sodium channel inhibition + increased GABA turnover, some action on Ca2+ channels
SE: N+V, hair loss, weight loss, toxic to liver / pancreas, teratogenic
Mechanism of action and side effects of Levetiracetam
Calcium channel inhibition / unknown. SV2A, regulates release of neurotransmitters.
SE: drowsy, dizzy, easy bruising, altered mood
Used in myoclonic / focal seizures
Mechanism of action Ondansetron, uses + SE
5-HT3 receptor antagonists
Uses: Chemo / radio –> GI tract damage
SE: Headache, dizziness, fatigue, constipation
Dopamine blockers used for anti-emetics, uses and SE
Domperidone, metoclopramide, haloperidol.
Uses: infection, metabolic, uraemia, drugs
SE: EPSE, urinary retention
Cyclizine mechanism of action, uses and SE
Antagonise ACh and Histamine in medulla oblongata
Uses: vertigo, raised ICP, urinary retention
Hyoscine hydrobromide mechanism of action
Muscarinic antagonist - M1-M4.
Reduced ACh –> reduced secretions
SE: Drowsiness, dry mouth, constipation, urinary retention
Mechanism of action of NSAIDs/ Paracetamol
NSAIDs COX-1 and COX-2 inhibitors –> reduced prostaglandin H2
Paracetamol selectively inhibits COX-2 more –> less anti-inflammatory effects. Absorbed in duodenum
How is paracetmol metabolised?
By the liver
1/3 into sulphate
1/2 into glucuronide
Rest into NAPQI - toxic if not conjugated with glutathione. In excess –> build’s up?
What is Reye’s syndrome?
Acute swelling and increased pressure in brain and liver
Secondary to viral infection. Aspirin contributes
Different types of drug reactions
Type A = Exaggeration of normal response
Type B = Unpredicatable eg anaphylaxis
Type C= After long time treatment eg osteonecrosis of jaw, visual fields with vigabatrin
Type D= Occurs years after Tx ended eg tarditive dyskinesia after antipsychotics
Type E= Once medicine is stopped eg withdrawal
Sx of Digoxin toxicity
Bradycardia
Hypotension
Hypoglycaemia
Hyperkalaemia
T wave flattening
Mechanism of ursodeoxycholic acid
Protects hepatocytes against bile-induced apoptosis in cholestasis
Inhibition of mitochondrial membrane permeability and transition stimulation of survival pathway
Mechanism of action chlorphenamine
H1-receptor blocker
How to convert IV to PO morphine
x2
Drugs that can affect the efficacy of OCP
Carbamazepine
Phenytoin
Phenobarbital
Topiramate, rifampicin.
–> Reduced activity of lots of drugs that are metabolised by the liver.
Mechanism of action: Azathioprine
Inhibits the synthesis of purine nucleosides and thus the proliferation of T and B lymphocytes and antibody formation.
Mechanism of action: Sulphasalazine
Eg in UC
Inhibits leukotrienes (inflammation)
