week 9 Flashcards
Kaolin
treatment for acute diarrhoea.
Bulk forming and adsorbent
Loperamide logP and pKa
logP= 4.5
pKa=9
lipophillic and charged
Drivers for the MCR service
improves clinical outcomes ad concordance, promotes self care, reduces hospital admissions, reduces waste, reduction in prescribing errors.
Who is eligible for MCR service?
new medications, high risk medications, smoking cessation, gluten free foods, have a chronic illness that requires medication.
Who is not eligible for serial prescription service?
unstable conditions, patients with frequent medication changes, medications requiring close monitoring/titrating, no long term indication, weekly or daily installments.
Benefits of serial prescribing
manages workload, reduces repeat prescribing in GPs, supports patients, increased direct contact with healthcare professionals (checkup consultations)
mucosal malabsorption
issues relating directly to small intestine wall
crohn’s, coeliac, surgery
pre mucosal malabsorption
nutrients aren’t available for absorption
pancreatitis, cystic fibrosis, lactase deficiency
Typical deficiencies in crohn’s
iron deficiency anemia
b12/folate deficiency
vitamin d and calcium deficiency
What is coeliac disease?
autoimmune condition where gluten activates an abnormal mucosal response. Chronic inflammation and damage to small intestine mucosa - villous atrophy.
Cystic fibrosis - sodium and chlorine levels
decreased chlorine secretion
increased sodium absorption
Water soluble vitamins
B , C
Fat soluble vitamins
A, D, E, K
Sources of cobalamin (vit b12)
meat fish dairy.
not synthesized within the body
RDA for b12
1-2.5 micrograms
Explain the two mechanisms of absorption of vitamin b12
Passive absorption; Though buccal, duodenal and ileal mucosa. Rapid but extremely inefficient. <1% of an oral dose is absorbed.
Active transport; Normal physiological mechanism is active transport. Occurs through the ileum mediated by gastric intrinsic factor. 70% of ingested amount is absorbed.
Absorption of b12 from food.
is released from food and bound to haptocorrin (haptocorrin is produced by the salivary glands and is a glycoprotein)
Intrinsic factor is secreted by parietal cells. On reaching the duodenum haptocorrin is degraded releasing vitamin b12.
Vitamin b12 is captured by intrinsic factor.
Intrinsic factor-bound vitamin b12 passes along intestine. In the terminal ileum, intrinsic factor-bound vitamin b12 is endocytosed by cubam.
Inside the enterocyte, intrinsic factor is degraded.
An ABC (ATP Binding Casset) transporter releases vitamin b12 into the blood.
Vitamin b12 binds to transcobalamin II.
Cellular uptake of b12
Vitamin b12 bound to transcobalamin II.
Internalization occurs in complex with transcobalamin receptor CD320 via endocytosis.
The transcobalamin is degraded, yielding vitamin b12. Excess b12 is sent to the liver for storage.
What is the role of intrinsic factor in absorption?
ensures adequate amounts of b12 are absorbed - reducing the chances of megaloblastic anemia.