Block 32 Pharm Flashcards
Antacids and alginates examples
- Magnesium trisilicate
- Aluminium/magnesium mixtures (Maalox) - Alginates
what are antacids and alginates used for?
dyspepsia, GORD
Mag trisillicate mechanism?
-antacid
- inc pH of gastric juicr via neutrilisation
CI of magnesium triscillicate?
Hypophosphataemia
mag tricillicate interactions?
- amlodepine
- nifedipine
- verapamil
mag trisillicate side effects?
- diarrhoea
- nephrolithiasis (long term use)
Co-magaldrox (Maalox) mechanism?
- mix of mag hydroxide and al hydroxide
- neutralises acid
Co-magaldrox indications?
dyspepsia
Co-magaldrox side effects?
constipation and diarrhoea
Co-magaldrox and renal impairment?
There is a risk of accumulation and aluminium toxicity with antacids containing aluminium salts
alginates mechanism?
- reacts w gastric acid to form a raft of alginic acid gel
- raft had a neutral pH
- acts as a barrier to impede reflux
CI of alginic acid?
- intestinal obstruction
- where excessive water loss likely (e.g. fever, diarrhoea, vomiting, high room temperature)
alginates and renal impairment?
avoid - risk of hypernatremia
alginic acid (gaviscon) side effects?
- ankle swelling
- constipation
H2-receptor antagonists?
rantidine
rantidine indications?
dyspepsia, GORD, peptic ulceration, prophylaxis of NSAID associated peptic ulceration
cautions with H2 receptor antagonits like ranitidine?
signs and symptoms of gastric cancer can be masked
ranitidine side effects?
- bone marrow depression
- nephritis
- acute pancreatitis
- dyskinesia
ranitidine mechanism?
- normally after a meal, gastrin -> histamine release -> H2 activation -> acid secretopm
- ranitidine blocks H2 receptors on gastric parietal cells -> less acid produced
PPIs?
- Lansoprazole
- Omeprazole
PPIs mechanism?
- inhition of the H+/K+/ATPase pump
- inhibition of acid production
PPIs and H pylori eradication?
- PUD associated w H pylori infection
- acid inhibition in H pylori eradication therapy raises gastric pH discouraging growth of H pylori
- PPI inhibit urease enzyme
PPIs indications?
- dyspepsia
- GORD
- oesophagitis
- peptic ulceration
- prophylaxis of NSAID associated peptic ulceration
- H. pylori eradication
cautions of PPIs?
- risk of fractures - high doses in the elderly
- C diff infection risk
- masking gastric cancer symptoms
- B12 abs reduced w long term use
- osteoporosis risk
side effects of all PPIs?
- abd pain
- constipation
- diarrhoea
- headache
- skin reactions
Opiate based anti-motility agents =
codeine
indications of codiene?
- diarrhoea
- short term pain relief
- dry cough
CI of codeine and all opiods?
- ARD
- comatose
- raised ICP
- risk of paralytic ileus
CI for codeine?
- active UC
- ab associated colitis
- children under 18
- known ultra-rapid codeine metabolisers
codeine interactions?
- buprenorphine
- clozapine
- naltrexone
- fluoxetine
side effects of codeine?
- arrhythmias
- constipation
- hallucinations
- nausea and vomiting on initiation
- urinary retention
Non-opiate based anti-motility agents =
loperamide
codeine mechanism?
- mu opiod receptors agonism
- g protein response
- hyperpolarisation of nociceptive neurons -> impaired pain transmission
loperamide mechanism?
- used for diarrhoea
- mu opiod agonist on the circ and longitudinal intestinal muscle
- inhibits release of ACh and prostaglandins -> reducing peristalsis -> inc intestinal transit time
loperamide indications?
- diarrhoea - acute and chronic
- faceal incontinence
loperamide CI?
- Active UC
- ab assoc colitis
- abd distension
loperamide interactions?
- clozapine
cautions of loperamide?
children under 12
side effects of loperamide?
- GI disorders
- headache
- nausea
Aminosalicylates?
- e.g. mesalazine
- IBD
mesalazine mechanism?
- induce and maintains remission
- inhibition of nuclear factor kappa B and blocks production of pro-inflamm cytokines
- blocks COX pathways - less leukotrienes
mesalazine CI?
- blood clotting abn
side effects of aminosalicyclates?
- cough
- fever
- leucopenia
- proteinuria
-*** pancreaTitis ** - ** agranulocytosis**
- peripheral neuropathy
corticosteroids?
Hydrocortisone,Prednisolone, Budesonide
corticosteroids indications?
IBD - Crohs earlier than UC
corticosteroids mechanism?
- neutrophil apoptosis
- inhibits phospholipase A2, and NF-Kappa B
- promote anti-inflammatory genes like IL10
CI for all corticosteroids?
- avoid live viruses
- systemic infection
steroids side effects?
- cushings syndrome
- psychotic disorder
- hirtutism
- HTN
- osteoporosis
- peptic ulcer
- inc weight
steroids and adrenal suppression?
During prolonged therapy with corticosteroids, particularly with systemic use, adrenal atrophy develops and can persist for years after stopping. Abrupt withdrawal after a prolonged period can lead to acute adrenal insufficiency, hypotension, or death
Immunosuppressants =
azathioprine -> Crohns
azathioprine mechanism?
- IS
- Purine synthesis inhibition
- inhibition of B and T cells
azathioprine Cl?
Reduced TPMT activity
azathioprine interactions?
- allopurinol
- BCG vaccine
- captopril
- HZ vaccine
- ACEi
- trimethoprim
azathioprine side effects?
- bone marrow depression
- leucopenia
- pancreatitos
- inc infection risk
- thrombocytopenia
pre-treament screening for azathioprine?
- TPMT activity
- increased risk of myelosuppression with reduced TPMT activoty
azathioprine monitoring?
- FBC weekly for first 4 weeks
- then at least every 3 months
- for risk of myelosuppression
cytokine inhibitors?
- Infliximab
- Adalimumab
cytokine inhibitors Ix?
Crohns
infliximab mechanism?
- binds to TNF-a
-> Downregulation of IL1 and IL6
adalimumab mechanism?
- TNF-a inhibition
CI of infliximab/ adalimumab?
moderate/ severe HF, severe infections
infliximab interactions?
- BCG vaccine
- cholera vaccine
- MMR vaccine
- HZ vaccine
- influenza vaccine
side effects of infliximab?
- alopecia
- arrhythmias
- hypotension/ hTN
- neutropenia
- vasodilation
- sepsis
pre-Tx screening w infliximab/ adalimumab?
TB
adalimumab side effects?
- agranulocytosis
- anx
- haemorrhage
- leucopenia, neutropenia, thrombocytopenia
adalimumab is assoc w ?
infections, sometimes severe, including tuberculosis, septicaemia, and hepatitis B reactivation.
Metronidazole & Vancomycin are used for
C diff assoc diarrhoea - colitis
metronizadole mechanism?
- high activity against anaerobic bacteria and protozoa
metronidazole interactions?
- disulfiram
- fluorouracil
- lithium
- warfarin
side effects of metronidazole - IV?
- Vomiting
- metallic taste
- nausea
- dry mouth
- vomiting
rare side effects w metronidazole
- panc
- agranulocytosis
- peripheral neuropathy
- cerebellar syndrome
metronidazole mechanism?
- nucleic acid synthesis inhibition
- anaerobic bacteria
vancomycin mechanism?
- prevens crosslinkage of peptidoglycan subunits
- prevents cell wall formation
- glycopeptide ab
cautions of vancomycin?
Systemic absorption may be enhanced in patients with inflammatory disorders of the intestinal mucosa or with Clostridioides difficile-induced pseudomembranous colitis (increased risk of adverse reactions)
side effects of vancomycin?
- agran
- eosinophilia
- hypersensitivity
- renal failure
Antiprotozoal agent e.g.
metronidazole