Pharmacology Flashcards
GORD
Reflux of acidic contents into oesophagus.
Symptoms: Burning sensation.
Worse when bending.
Causes: Weak sphincter, Increased abdominal pressure; Pregnant, Obese.
Gastritis
Inflammation of stomach lining.
NSAIDs
Alcohol
Peptic Ulceration
H. pylori infection --> Gastritis --> Ulceration Symptoms: Sharp stabbing pain-precise. Vomiting blood Nausea
Dyspepsia warning signs
Over 55 Tarry stools Weight loss Trouble swallowing Vomiting blood
Cephalic phase
Anticipation of food Parasympathetic --> Ach --> Acid Release --> Gastrin Release
Gastric Phase
Distension by food (eaten) Ach, Histamine, Gastrin released. Ach --> Acid release --> Pepsinogen release --> Peptide fragments -->Stimulate G cells--> More acid release. --> Mucus release Histamine --> Acid release. Gastrin --> Acid release.
Intrinsic factor
Produced by parietal cells.
Promotes vitamin B12 absorption.
Vitamin B12 cofactor in blood cell production.
Saliva production
Parasympathetic–>Ach–>Muscarinic –> Enzyme secretion
–>Vasodilation
Vasodilation caused by
BRADYKININ
Acetylcholine
Vagus nerve –> Ach –> M3 –> PHOSPHOLIPASE –> Ca2+ = Proton Pump Activated
Histamine
Histamine –> H2 –> α unit unbinds –> GDP –> GTP
–> Adenylyl Cyclase
Adenylyl Cyclase –> AMP –> cAMP
cAMP phosphorylates proton pump.
Gastrin
Released by antral cells.
CCK2 receptors
Ca2+–> Proton pump activated
Arachidonic acid
Cell membrane (released by Phospholipase A2) –> Arachidonic acid –> (Cox pathway) Prostaglandins
Prostaglandins
PGE2 and PGI2 inhibit cAMP increase
Supress proton pump
ALSO: Pain, inflammation etc
NSAIDs
Stop COX –> Stop prostaglandins –> increase acid
–> stop pain etc
Aspirin: Not for pain, inflammation etc. Use for antiplatelet
Antacids
Sodium bicarbonate Magnesium hydroxide (Diarrhea) + Aluminium hydroxide (constipation)
Alginates
Raft forming
Alginic acid + saliva = viscous foam
H2 receptor antagonists
Cimetidine (Inhibits CYP450)
Ranitidine (Zantac)
Famotidine
-Best given at night
EC50
Concentration of agonist that gives 50% response.
PPI’s
Omeprazole (OTC)
Pantoprazole (OTC)
Lansoprazole
- Avoid prolonged use; rebound acid hypersecretion
- Bind to cysteine residues in proton pump
Prostaglandin analogues
Misoprostol
Inhibit cAMP rise
Suppress acid release.
H. pylori treatment
Triple Therapy: 2 Antibiotics: Clarithromycin (Drug interactions) Amoxicillin (Penicillin allergy?) Metronidazole (NO ALCOHOL)
1PPI
Erythropoiesis
- Production of RBC
- Controlled by Erythroprotein (EPO)
- Released by peritubular cells in kidney
Reticulocyte
- Immature RBC
- Retic count elevated when more erythropoiesis; Bleeding?
Fe2+
- From diet
- Fe3+ produced by mucousal cells of duodenum.
- Bind to apoferritin
- Releaseed into blood, binds to transferrin.
- Iron to bone marrow.
- Iron to Hb.
WBC
Neutrophils-Phagocytosis
Eosinophils-Parasite
Basophils-Histamine
Lymphocytes-Antibodies
Production: Colony stimulating factors (proteins)
Haematocrit
Packed cell volume
% volume that is RBC
Mean corpuscular volume
Volume of individual RBC
Measured in fl=10-15 of a litre
Blood Groups
A: A antigens, B antibodies
B: B antigens, A antibodies
AB: AB antigens
O: No antigens but a + b antibodies
Rhesus D
- Mother Rhesus -ve
- Child Rhesus +ve
- Mother produces antibodies against Rhesus D
- Antibodies attack 2nd child.
Anaemia symptoms
Shortness of breath
Weakness
Lethargy
Tachycardia-Higher heart rate as thin blood
Iron deficient anaemia
Microcytic (smaller RBC)
Causes: Diet (rare), Menstruation, Pregnancy
Megaloblastic anaemia
Macrocytic (larger RBC)
Defective DNA synthesis, bone marrow contains megaloblasts.
VitB12/Folate deficiency.
Pernicious anaemia
Lack of intrinsic factor for B12 absorption
Autoimmune disease
Haemolytic anaemia
Higher rate of RBC destruction
Spherocytosis: Genetic, Abnormal reduction in RBC membrane protein, cells fragile.
Sickle Cell anaemia
Genetic
Abnormal Hb, RBC=Sickle shape
Block microcirculation, causes haemolytic anaemia
Aplastic anaemia
Insufficient production of RBC, WBC + Platelets
Tired, Bleeding, Infections
Causes: Viral, drugs
Polycythaemia
Higher RBC Higher blood viscosity Causes: Primary-Bone marrow Secondary-More EPO; Altitude, smoking