Medicines 8 Flashcards
What particular meds should be avoided with macrolides
warfarin, tacrolimus, statins.
What are some key points regarding antihypertensives
-Single agent normally adequate. Titate to optimum highest tolerated dose at each step before adding further treatment
systolic + diastolic
- Afro-carbbean or black African = ARB> ACE
- Pregnancy = AVOID ACE-i + ARBS
- Breastfeeling= Benefits + risks of ACE-i+ARBS discussed with women
How do GLP-1 receptor agonists work ?
“TIDE”
How GLP-1 Receptor Agonists Work
GLP-1 receptor agonists (glucagon-like peptide-1 receptor agonists) are a class of medications that mimic the action of the natural incretin hormone GLP-1. This hormone is involved in regulating glucose metabolism and appetite. Here’s how they work:
1. Enhance Insulin Secretion:
• GLP-1 receptor agonists stimulate the pancreas to release insulin in response to meals, reducing blood sugar levels.
2. Inhibit Glucagon Secretion:
• They suppress the release of glucagon, a hormone that raises blood sugar levels by promoting glucose production in the liver.
3. Slow Gastric Emptying:
• By delaying the movement of food from the stomach to the intestine, they help reduce post-meal blood sugar spikes.
4. Reduce Appetite:
• They act on receptors in the brain to promote satiety, leading to reduced food intake and potential weight loss.
5. Cardiovascular Benefits:
• Some GLP-1 receptor agonists have been shown to reduce cardiovascular risk in people with type 2 diabetes.
What are the different formulations of the GLP-1 receptor agonists ?
semaglutide - oral preparation + injections (Ozempic)
Liraglutide - Saxenda + Victoza
Tirzeptide - Mounjaro
Dulaglutide - Trulicity
What is the FAST acronym for stroke
Face weakness: Can the person smile? Has their mouth or eye drooped?
Arm weakness: Can the person raise both arms fully and keep them there?
Speech problems: Can the person speak clearly and understand what you say? Is their speech slurred?
Time to call 999: if you see any one of these signs.
List some enzyme inducers and what they are:
Enzyme inducers are medications that increase the activity of enzymes, particularly those in the liver, such as cytochrome P450 enzymes
Anticonvulsants: phenytoin, carbamazepine, phenobarbitone
Steroids: dexamethasone, prednisolone, glucocorticoids
Antibiotics: rifampicin, griseofulvin
Others: nicotine, alcohol, cigarette smoke, St John’s Wort
**Mnemonic: “Cigarettes And Alcohol Really Push Enzymes And Smoking Speeds Metabolism”
Breakdown:
Cigarettes: Nicotine and Cigarette Smoke
And: Alcohol (chronic use)
Antibiotics: Rifampicin, Griseofulvin
Really: Rifampicin
Push: Phenytoin
Enzymes: Phenobarbitone (Barbiturates)
And: Alcohol
Smoking: St. John’s Wort
Speeds: Steroids (Dexamethasone, Prednisolone, Glucocorticoids)
Metabolism: Reminder that these all increase drug clearance.
List some CYP450 enzyme inhibitors:
Examples of CYP450 inhibitors include::
Azoles: ketoconazole, fluconazole
Antibiotics: sulfonamides, metronidazole, ciprofloxacin, chloramphenicol, macrolides, isoniazid
Cimetidine
Omeprazole
Sodium valproate
Grapefruit
List some CYP450 enzyme substrates
Enzyme substrates are drugs or other substances that bind to and are metabolised by the CYP450 enzymes
Examples of CYP450 substrates include:
Statins
Theophylline
Phenytoin
Warfarin
Selective serotonin reuptake inhibitors (SSRI): sertraline, citalopram, fluoxetine
Amitriptyline
Codeine
Caffeine
What is the relationship between enzyme inducers, substrates and inhibitors?
Inducers increase metabolism → Lower drug levels → May need higher substrate doses.
Inhibitors decrease metabolism → Higher drug levels → May need lower substrate doses.
Substrates + Inducers:
An enzyme inducer increases the metabolism of a substrate, leading to:
Reduced drug levels in the body.
Possible therapeutic failure (e.g., reduced efficacy of oral contraceptives when taken with rifampicin).
Clinical Implication: May require dose increase of the substrate to maintain efficacy.
Substrates + Inhibitors:
An enzyme inhibitor decreases the metabolism of a substrate, leading to:
Increased drug levels in the body.
Possible drug toxicity (e.g., warfarin with fluconazole increases bleeding risk).
Clinical Implication: May require dose reduction of the substrate to avoid toxicity.
Inducers + Inhibitors:
If an inducer and an inhibitor are given together, their effects may partially or completely cancel each other out, depending on their relative strengths.
Example: Rifampicin (inducer) + ritonavir (inhibitor) in HIV therapy may require careful adjustment of doses.
What are the antidotes for the following?
Benzodiazepines
digoxin
heparin
Opioid
paracetamol
dabigatran
Other Doacs
Beta blockers
warfarin
Poisoning
Methotrexate
Benzodiazepines - Flumazenil
digoxin -digoxin specific antibody
heparin - Protamine sulphate
Opioid - Naloxone
paracetamol - Acetylcysteine
dabigatran - Idaracizumab
Other Doacs - Dexanet Alpha
Beta blockers -Atropine
warfarin - Phytomenadione (vitamin K1)
Poisoning - Activated charcoal (reduces absorbtion)
Methotrexate - Glucarpidase
Which antibiotics is usually given for the following:
Skin-Staphylococcus
Respiratory - Streptococcus
UTI - E.Coli
GI - C.Diff
- H.Pylori
Skin-Staphylococcus - Flucloxacillin
Respiratory - Streptococcus - Amoxicillin, Clarithromycin, doxycycline
UTI - E.Coli - Nitrofurantoin, trimethoprim
GI - C.Diff, vancomycin/Fidoxamicin
- H.Pylori, Amoxicillin + clarithromycin or metronidazole +PPI (BD) - Always use ONE proton pump inhibitor (PPI) PLUS TWO antibiotics.
Which medications can cause low vitamin B12 (hydroxocobalamin)
- Psychiatric disturbances, neuropathy, muscle weakness
Metformin
Colchicine
PPIs
What medications can cause an increased risk of diabetes?
Antipsychotics
Phenytoin
Tacrolimus
Theophylline (aminophylline)
Corticosteroids
Thiazide diuretics
Loop diuretics
Beta blockers
SAM CHECK THIS!
Name the different LAMAs and SAMAs
Ipatropium ( SAMA)
LAMAs:
Aclidanium
Tiotropium
Ulmeclidinium
Glycopyrium
Name some SABAs and LABAs
SABA
Salbutamol
Terbutaline
LABA
Formoterol
Indaciaterol
Clodaterol
Salmeterol
