Resp Drugs Flashcards
B2 Agonist Mechanism (Resp)
+Adenylyl Cyclase converting ATP to cAMP
cAMP activates PKA -> Bronchodilation
B2 Agonist Examples + SEs (Resp)
SABA: Salbutamol, Terbutaline
LABA: Salmeterol, Formoterol
SABA Overuse
- Tremor, headache, muscle cramps, palpitations
- HyPOkalaemia
- Myocardial ischaemia?
LABA ⇒ Above + Increase asthma-related adverse events
- Do not start before Steroid, and do not stop Steroid while on LABA
B2 Agonist Indications (Resp)
Asthma 1st: SABA
3rd: LABA
Severe: Nebulised COPD: 1st
- SABA
- Inhaled Steroid (200-800mcg/d)
- LABA
-
+ Increase Inhaled Steroid (upto 200mcg/d)
+ Leukotriene receptor agonist
or + Theophylline (methylxanthine PDE inhibitor) - Prednisolone Tablet
Anticholinergics Mechanism (Resp)
Muscarinic antagonist Inhibit bronchial mucus secretion
Anticholinergic Examples (Resp)
- Ipratropium
- Tiotropium
Anticholinergic Indications (Resp)
Asthma Severe: Nebulised Ipratropium
COPD: 1st
Methylxanthine Mechanism (Resp)
Inhibits phosphodiesterase
STOPs cAMP to AMP conversion
Increasing cAMP -> Activates PKA -> Bronchodilations
Methylxanthine Examples + SEs (Resp)
- Theophylline
- Aminophylline
- Therapeutic plasma concentration = 10-20mg/L
SEs
- N+V
- Tremor
- Palpitations + Arrythmias
Increased serum levels
- HF + Hepatic failure
- Elderly
- P450 inhibitors (cimetidine, ciprofloxacin, erythromycin)
Decreased serum levels
- P45 inducers (phenytoin, carbamazepine, rifampicin)
Methylxanthine Indications (Resp)
Asthma: 4th
COPD: 2nd
Glucocorticoid Mechanism (Resp)
Bind glucocorticoid receptor, modify gene transription;
- Inhibit COX2, cytokines, cell adhesion moleules
- Inhibit IL4,5,13 from Th2 cells
- ++anti-inflammatory genes
Glucocorticoid Examples + SEs (Resp)
- Inhaled: Beclometasone, Fluticasone, Budesonide
- Ciclesonide (pressurized MDI), Mometasone (dry-powder inhaler)
- Oral: Prednisolone, Hydrocortisone
Inhaled Local SEs
- Oral candidiasis, sore mouth, dysphonia, hoarseness
- Reduced using large-volume spacer (filters)
- +Wash mouth after use
Inhaled Systemic SEs
- Osteoporosis (exercise, calcium, stop smoking)
- HPA suppression
Inhaled Child Systemic SEs
- Initial slowing, final height not affects
- >100ug/d ⇒ Growth suppression + Adrenal crisis
- Very rare: Hyperactivity, behavioural problems, sleep, anxiety, depression
Oral (especially >3m/ frequent)
- Central obesity + Weight gain
- UUUN face
- Skin - thin, easy bruising, acne, hirsutism
- HyPERglycaemia + DM + HyPERtension
- Insufficient muscles (proximal weakness)
- Neck buffalo + supraclavicular lump
- Gonadal dysfunction +Glaucoma/ Cateracts
- Osteoporosis
- Immunosuppresion + Infections
- Depression
Glucocorticoid Indications (Resp)
Chronic asthma
- 2nd: Inhaled Low-Dose 200ug twice daily (Beclometasone)
- 5th: Oral Prenisolone
Acute asthma
- Prednisolone tablet 40mg (max 60mg) for 5d
or IV hydrocortisone (preferably Sodium Succinate) 100mg slow IV bolus if severe or more - Prednisolon daily dose
or Hydrocortisone 6hrly - Discharge: Oral steroids 5d
+add inhaled steroid to regular medication
COPD: 2nd Beclometasone
Anti-leukotriene Mechanism (Resp)
- Zileuton
* Inhibits 5-lipoxygenase (enzyme that converts arachidonic acid to Leukotriene A4) - Zafirlukast, Montelukast
* Inhibits CysLT1 (receptor for Leukotrienes)
Anti-leukotriene Examples + SEs (Resp)
- Zileuton (inhibits 5-lipoxygenase)
- Zafirlukast (inhibits CysLT1)
- Montelukast (inhibits CysLT1)
SEs
- Zafirlukast: Liver toxicity (any signs do ALT)
- N+V, malaise, jaundice
Anti-leukotriene Indications (Resp)
Asthma: 4th
