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.
What is the type of anemia that is due to the absence of intrinsic factor?
pernicious anemia
What can vitamin b12 deficiency be caused by?
diet, loss of gastric parietal cells or intrinsic factor, functionally abnormal intrinsic factor, bacterial overgrowth in intestine, disorders of plasma transport, dysfunctional uptake of b12
Consequences of low b12
paraesthia, sensory loss, gait ataxia, weakness in legs, infertiltiy, angina, dry tounge (Hunters glossitis)
What can be used to treat b12 deficiency?
oral cyanocobalamin or parenteral hydroxycobalamin
Sources of b9 (folate, folic acid)
green leafy vegetables, fruit, meat, seafood and fortified breads and cereals.
RDA of b9
200 micrograms, 400 during pregnancy
Absorption of folate
Natural folates are conjugated to a polyglutamyl chain but absorbed in the monoglutamate form - hydrolyzed
Most absorption occurs in small intestine (duodenum and jejunum) with there being some absorption in the colon.
Folate is absorbed form the lumen by a proton-coupled folate transporter PCFT.
Absorption is also via a reduced folate carrier RFC with folate being exchanged for organic phosphate OP .
Enterocytes also have folate receptors (binds folate and internalizes it by receptor mediated endocytosis).
Cellular uptake of folate
Most is transported as mono- glutamyl derivative. Most folate circulates free in the blood - some bound to albumin. Cellular uptake is by endocytosis.
Causes of folate deficiency
inadequate dietary intake. Congenital defects in the uptake system. Intestinal disease. Drug interaction e.g., cholestyramine, sulfasalazine, trimethoprim, methotrexate, metformin. Chronic alcohol use.
Results of b9 deficiency
- Sore tongue (glossitis) and pain upon swallowing
- GI symptoms (nausea, vomiting, abdominal pain diarrhoea, especially after meals)
- Neurologic (cognitive impairment, dementia, and depression)
- megaloblastic anaemia
Treatment of b9 deficiency
oral folic acid for 1-4 months.
What are the three types of stoma?
colostomy, ileostomy and urostomy
Explain what a colostomy is.
Two types;
Loop - bowel is lifted above skin level and formed in a stoma, essentially two stomas in one. Is generally temporary.
End - part of bowel removed, remaining bowel is brought to the surface
Generally on left side of body
Explain what a ileostomy is.
Usually created on right side of abdomen. Can be temporary or permanent. Bowel is brought to the surface of skin
Techniques for analysing pharmaceutical products.
UV/Vis spectroscopy
High pressure liquid chromatography
Techniques for analysing the solid product.
Infrared spectroscopy
X-ray diffraction
Column chromatography
Put in order of energy level absorbance (lowest to highest)
Electronic rotational vibrational
Rotational Vibrational Electronic
Rotational absorbs __ radiation
microwave
Electronic responds to __
UV light
Why are curves in a UV spectroscopy broad rather than sharp?
it is an average of all energy level values.
What does the slit do in a conventional spectrophometer?
selects wavelengths from the polychromatic light
Describe the action of a PDA spectrophotomer
whole spectrum is directed toward photodiode array.
No need for repeats, as collects wavelength data simultaneously.
Absorption of IR causes transitions in __
vibrational energy levels, rotational energy levels
Molecular bending variations
In-plane rocking
In-plane scissoring
Out of plane wagging
Out of plane twisting
Do amorphous forms diffract?
no
What are borderline substances?
nutritional or dermatological products that have been specially formulated to manage a medical condition e.g. gluten free foodstuffs
Purpose of a diluent in tableting?
increase weight and help uniformity.
E.g. mannitol, lactose, sorbitol
Purpose and example of binder in tableting?
holds all components together and gives mechanical strength. Provides volume in low dose formulations
E.g. starch, methyl cellulose
Purpose and example of glidant in tableting?
Helps powder to flow into the tableting machine.
e.g. palmitates and stearates ie fatty acids
