prescribing Flashcards
information from the prescribing questions
FP10D
yellow and issued by dentists
FP10MDA
blue
e.g. methadone
what should an FP10 include?
prescriber's signature prescriber's address date patient details information about product supplied
prescription charge
£8.60 (1st April 2017)
routes of administration
name 5
oral (po) intravenous (iv) rectal (pr) subcutaneous (sc) intramuscular (im) intra-nasal (in) topical (top) sublingual (sl) inhaled (inh) nebulised (neb)
vaccines given at 8 weeks
5 in 1: diphtheria, tetanus, whooping cough, polio, Hib
pneumococcal
rotavirus
meningitis B
administration routes of paracetamol
orally, per-rectum, intravenous
how do NSAIDs work?
inhibit cycle-oxygenase which catalyses the synthesis of prostaglandins and thromboxane from arachidonic acid
COX-1 is present in normal cells
COX-2 is induced by inflammatory cells
contraindications for NSAIDs
name 3
active or recurrent GI bleeding, active or recurrent GI ulceration, GI bleeding or ulceration related to NSAID use, severe heart failure, allergy to aspirin, renal failure, dehydration
use NSAIDs ‘with caution’ in patients with…
name 4
allergic disorders, cardiac impairment, cerebrovascular disease, coagulation defects, connective tissue disorders, Crohn’s disease, elderly, heart failure, ischaemic heart disease, peripheral arterial disease, risk factors for cardiovascular events, ulcerative colitis, uncontrolled hypertension
aspirin (and other NSAIDs) in asthmatics:
may cause bronchospasm (8-20%)
patients with chronic rhinitis or a history of nasal polyps are at greater risk
how do NSAIDs cause renal dysfunction?
they inhibit the biosynthesis of prostaglandins which maintain renal medullary blood flow
which patients are at risk of renal dysfunction caused by NSAIDs?
neonates elderly patients with heart disease patients with liver disease patients with renal disease patients with a reduced circulating blood volume
acute interstitial nephritis
a less common cause of renal impairment that becomes apparent after many months of NSAID use
how is metformin excreted?
it is cleared by active tubular secretion and is excreted unchanged in the urine
what is the elimination half life of a drug?
the time required for the serum concentration of the drug to reduce by 50%
what is there a risk of for patients on metformin given IV contrast?
lactic acidosis (mortality of 30-50%)
if more than 100ml of contrast is used, metformin should be withheld for 48hrs beforehand
if serum creatinine is normal the month before, <100ml of contrast may be given
which drugs require dose adjustment in renal impairment?
drugs that are excreted unchanged in the urine
esp. those with a narrow therapeutic index
ramipril
angiotensin converting enzyme inhibitor
what does ACE do?
it converts angiotensin I to Angiotensin II (a vasoconstrictor which also stimulates the release of aldosterone)
what do ACE inhibitors cause?
vasodilation and potassium retention
inhibition of salt and water retention
when should renal function be checked for patients on ACEi?
before starting the drug, and 2-4 weeks after any increase in dose
check periodically during treatment, especially if there is renal impairment (patient is at risk of hyperkalaemia)
how many patients get an ACE inhibitor cough?
10-30%
it is more common in women
why does an ACE inhibitor cough occur?
accumulation of kinins in the lungs
why are afro-carribean patients rarely given ACEi?
they commonly have low renin essential hypertension, where the RAAS is not contributing much to their hypertension
options for contraception
name 4
contraceptive pill, contraceptive patch, vaginal ring, contraceptive injection, contraceptive implant, intra-uterine device, intra-uterine system, condoms, female condoms, contraceptive cap, contraceptive diaphragm
the combined oral contraceptive pill
contains oestrogen and progesterone
suppresses ovulation by interfering with the gonadotrophin release by the pituitary via negative feedback on the hypothalamus –> prevents LH surge which triggers ovulation
cause the endometrium to become thinner which prevents implantation
cervical mucous becomes thicker –> more difficult for sperm to reach egg
loperamide
opioid receptor agonist
reduces GI tract motility
allows more water to be absorbed from faecal matter
what is folic acid needed for?
synthesis of thymidylate and purine nucleotides (therefore, it is needed for DNA synthesis)
what is the action of methotrexate?
methotrexate is a reversible competitive inhibitor of dihydrofolate reductase (DHFR) - it prevents nucleic acid synthesis and causes cell death
folic acid for patients on methotrexate
5mg once weekly on a different day to the methotrexate
monitoring of patients on methotrexate
FBC, renal and liver function tests before starting treatment and repeated every 1-2 weeks until therapy stabilised
after this point, monitor patients every 2-3 months
doxazasin
alpha-1-adrenergic receptor antagonist
antihypertensive
tamsulosin
subtype-selective alpha-1-A and alpha-1-D adrenoreceptor antagonist
intraoperative floppy iris syndrome (IFIS)
observed during cataract surgery in patients on alpha blockers - patient should let their surgeon know before the operation that they are taking them
alpha blockers side effects
postural hypotension - try taking them at night to reduce problems
retrograde ejaculation in 30% men
cyclosporin
T-lymphocyte suppressor of Th1 cells
inhibits production of interleukin-2 and other cytokines activated by lymphocytes
therapeutic index
the range of doses at which a medication is effective without unacceptable adverse events
drugs with a narrow therapeutic index
name 5
cyclosporin, gentamicin, vancomycin, warfarin, lithium, digoxin, theophylline, methotrexate, phenytoin, insulin
how to monitor drugs
plasma concentrations (phenytoin) clinical effects (anti-hypertensives) blood tests (warfarin and INR)
how to take alendronic acid
take the tablet whole with plenty of water while sitting or standing
take on an empty stomach at least 30 minutes before breakfast
stay upright for at least 30 minutes after taking the tablet
when to stop taking aldenronic acid and seek medical attention
symptoms of oesophageal irritation such as dysphagia, heartburn, pain on swallowing, or retrosternal pain
letrozole
used in post-menopausal women with oestrogen receptor positive breast cancer
long-term use can contribute to osteoporosis (give alendronic acid and AdCal (vitamin D))
action of alendronic acid
oral bisphosphonate
inhibits osteoclast mediated bone resorption
St John’s Wort
herbal medicine used to treat the symptoms of mild and moderate depression
St John’s Wort interactions
name 3
SSRIs, oral contraceptive pill, warfarin, cyclosporin, HIV medication, digoxin, statins
first line medication for moderate depression
selective serotonin reuptake inhibitor
prophylaxis
treatment given or an action taken to prevent disease
clenil modulate
used for prophylaxis of asthma
salbutamol
used to treat acute symptoms of asthma during exercise
spacer
an add-on device used to increase the ease of administering aerosolised medication from a metered dose inhaler
