Antibiotics.
CH3 CH3 CH3 CH2 CH2 CH2 CH2 CO O N +
The relationship between pH and the ionization of weak acids and bases.
A negative exponential decay curve.
The law of mass action governs drug-receptor interactions, making the rate of interaction proportional to the concentration of drug and receptor.
They become more ionized as they accept protons.
Highly lipid-soluble drugs, such as fentanyl.
A receptor is a protein, usually integral to the cell membrane, with selective ligand-binding sites.
It avoids first-pass metabolism and is useful when nausea and vomiting are problematic.
pK a is the negative log of the acid dissociation constant (K a) and indicates the pH at which a drug is 50% ionized and 50% unionized.
Plasma concentration of the drug.
Ethanol.
Larger particle sizes dissolve more slowly, affecting absorption rates.
In the highly acidic stomach.
36% cis-trans, 58% trans-trans, and 6% cis-cis.
To modify or degrade drugs to activate, deactivate, toxify, or detoxify them in the body.
No, you must learn this property for each drug.
A ligand is any substance able to bind to a receptor and bring about biological change within the cell.
Digoxin.
Compounds that have the same molecular formula and chemical structure but different spatial arrangements.
G_s, G_i, and G_q.
Nicotinic acetylcholine receptor (nAChR).
Reasons other than reduced renal elimination.
It reduces systemic absorption and provides a localized effect, but opioids may still cause respiratory depression.
It activates Protein Kinase A, leading to a phosphorylation cascade.
The drug’s increasing concentration gradient as water is reabsorbed along the tubule.
Furosemide.
In the un-ionized state.
A weak acid/base dissociates in water to form an equilibrium with its ions, while a strong acid/base dissociates readily without forming an equilibrium.
A stereoisomer that possesses a single chiral centre and forms a mirror image of each other but cannot be superimposed.
It initiates a signaling cascade that leads to various cellular responses.
CH3 N H CH2 C OH HO HO
It affects the intensity and duration of the drug's action.
They become less ionized.
C_p = C_0 . e^(-k.t)
Occurs when the combined action of two or more drugs is greater than the sum of their individual effects (i.e. 1 + 1 > 2). Example: propofol and remifentanil.
It reveals the C sub-unit of Protein Kinase A.
Seconds.
Weak acids or weak bases.
Pancuronium.
The passage of a drug into the bloodstream from its route of administration.
Occurs when the action of two or more drugs is additive (i.e. 1 + 1 = 2). Example: nitrous oxide and inhalational anaesthetic agents.
It is crucial for oxidation reactions and shows genetic variability; its activity can be induced or inhibited by other drugs or chemicals.
Reactions that involve adding groups to drugs, increasing their water solubility for excretion.
In the intestine where pH is higher.
They can be classified as physicochemical, pharmacokinetic, and pharmacodynamic interactions.
Gq proteins stimulate phospholipase C, causing a rise in IP3 and DAG.
Sodium nitroprusside.
pH = pKa + log([A-]/[HA]) or pH = pKa - log([HA]/[A-]).
It metabolizes drugs in the liver.
The larger the pK a, the less readily the acid dissociates, affecting the drug's ionization and absorption in different pH environments.
Plasma concentration at time zero.
Bioavailability describes the fraction of the drug administered that reaches the bloodstream.
Inositol 1,4,5 Triphosphate (IP3) and Diacyl Glycerol (DAG).
Phase I and Phase II reactions.
The release of Ca2+ from the endoplasmic reticulum (ER).
A drug interaction occurs when the action of one drug is altered by the concurrent or prior administration of another drug.
Occurs when the action of one drug is increased by the administration of another drug. Example: probenecid increases the action of penicillin by reducing its renal excretion.
An amphoteric compound can behave as either an acid or a base, such as water.
An atom, usually carbon or nitrogen, bonded to four different atoms or groups.
It can cause progressive inflammatory liver damage, leading to fatty liver and cirrhosis.
The pK a value helps predict the ionization state of a drug at a given pH, influencing its absorption and efficacy.
cAMP, cGMP, IP<sub>3</sub>, DAG, and calcium ions (Ca<sup>2+</sup>).
Phosphatidylinositol 4,5 Biphosphate.
Increased H+ concentration drives the equation to the left.
7.6.
G proteins (or GTP-binding proteins) are regulatory proteins that couple the activation of a surface receptor to the activation of an intracellular enzyme, allowing signal transduction and amplification.
Enantiomers and diastereoisomers (optical isomers), and cis–trans isomers (geometric isomers).
They may require further modification and undergo Phase II reactions for excretion.
Gs proteins stimulate adenylate cyclase, causing a rise in cAMP.
A tyrosine kinase linked receptor.
50%.
They occur when one drug alters the way in which the body handles another drug.
Inhalational anaesthetic agents.
N H H CH2 C OH HO HO
Analgesics.
Renal elimination may be decreased, requiring dose adjustments.
They are specific, dose-dependent, and saturatable.
8.4.
G proteins are heterotrimeric proteins consisting of α, β, and γ subunits.
It results in reduced drug plasma protein binding, increasing the free, active component of the drug.
One in six drug charts contains a significant drug interaction.
It describes a situation where the rate of change of a substance is directly proportional to the quantity of that substance at that time.
By comparing the plasma concentration of the drug when administered orally to that when administered intravenously.
Isomers can have different pharmacodynamic and kinetic properties despite having the same molecular formula.
Gene transcription.
Their metabolism is impaired and effects are enhanced; they should be avoided.
Aspirin.
G<sub>i</sub> proteins, such as via stimulation of α<sub>2</sub> adrenoceptors and opioid receptors.
The groups are arranged on opposite sides of the double bond.
It is an energy-dependent process and carrier mediated.
It consists of seven α helices that span the cell membrane.
N H H CH2 C OH HO HO
Drugs that need to be metabolised to become active, such as enalapril, which is converted to enalaprilat.
It indicates the pH at which the drug exists as 50% ionized and 50% un-ionized.
Oxidation, reduction, or hydrolysis of the drug.
Route of administration, particle size, pKa and ionization, lipid solubility, concentration gradient, and other factors like bacterial overgrowth.
Porto-caval shunts in cirrhosis reduce hepatic blood flow, decreasing the drug extraction ratio.
They remain in the urine and are not reabsorbed, e.g., digoxin and aminoglycoside antibiotics.
The rate constant.
It alters their degree of ionization and consequently their lipid solubility, affecting their speed of elimination.
It leads to an increase in the volume of distribution of drugs due to increased total body water.
By a combination of metabolism by the liver and excretion via the kidneys.
They occur due to the physical properties of the drugs themselves.
Enteral, intravenous, transdermal, intranasal, sublingual, intrapulmonary, and intramuscular.
By activating protein kinases and modulating calcium channels.
It damages liver cell and mitochondrial membranes, generates free radicals, and stimulates the immune system.
It influences the ionization and solubility of the drug, affecting its availability for absorption.
Precipitation: Thiopentone (weak acid) and suxamethonium (weak base).
The duration of action is prolonged due to decreased plasma cholinesterases.
30%.
Aspirin displaces warfarin from plasma proteins, increasing the unbound fraction of warfarin and the risk of bleeding.
The normal phenotype is eu (usual), allowing rapid breakdown of suxamethonium.
The percentage inhibition of benzylcholine breakdown by plasma cholinesterase in the presence of dibucaine; normal is 75-85, abnormal homozygotes can be as low as 30.
Phenothiazines, paracetamol, and steroids.
Because they can more easily diffuse through cell membranes.
Glucuronidation, sulphation, acetylation, and methylation.
When the two groups around the double bond are identical.
It causes a conformational change that opens a central pore allowing an influx of Cl<sup>-</sup> ions.
They are extensively reabsorbed at the level of the kidney tubules.
Renal function decreases with age, leading to reduced drug elimination and increased risk of acute renal failure.
Esomeprazole has higher bioavailability than omeprazole.
Chelation: Sugammadex and rocuronium.
Compounds that have the same molecular formula but different chemical structures.
They diffuse into the cell, bind to intracellular receptors, and alter DNA transcription.
6–8 hours.
15–30%.
It acts as an agonist.
It can secrete drugs against their concentration gradients and is efficient even for highly protein-bound drugs.
It can lead to prolonged drug action and increased incidence of adverse effects, such as prolonged neuromuscular block.
Steroid receptors as an agonist.
It increases it.
Propofol is an anaesthetic drug commonly used in medical settings.
As pH increases, the percentage of un-ionized weak bases increases, while for weak acids, it decreases.
The main types of G proteins are stimulatory (Gs and Gq) and inhibitory (Gi) proteins.
A higher K a value indicates that the acid more readily gives up its proton and dissociates.
1.0 or 100%.
'dc' is the change in drug concentration and 'dt' is the change in time.
They have low oral bioavailability, and an alternative route of administration may be necessary.
They occur when the action of one drug is altered by the administration of another drug.
They should be used with caution and in reduced doses due to impaired metabolism and enhanced effects.
60%.
Conditions like liver disease can decrease plasma protein production, altering drug binding and metabolism.
Reduced glomerular capillary plasma flow rate and ultrafiltration coefficient.
It increases the renal excretion of salicylates.
It varies among individuals: poor metabolizers get little relief, extensive metabolizers get good relief, and ultra-extensive metabolizers may risk opioid toxicity.
It acts as an agonist.
It inhibits cyclo-oxygenase 1 and 2.
It chelates rocuronium.
The pH of a solution and the proportions of ionized and un-ionized drug at a given pH.
A specific site on the GABA<sub>a</sub> receptor.
It leads to prolonged action of these drugs.
Elderly patients are often volume depleted, which may decrease the volume of distribution of drugs.
It prevents dissolution in acidic conditions, allowing the drug to dissolve in the basic intestine.
Men have higher levels of alcohol dehydrogenase than women, affecting alcohol metabolism.
They possess a double bond around which the attached atoms cannot rotate.
Morphine or Diltiazem.
Isomers where the carbon skeleton varies but the functional group remains in the same position.
Drugs of low molecular weight (<60,000 daltons) that are not plasma protein bound, e.g., fluconazole and ofloxacin.
Verapamil.
Recovery time is extended to around 30 minutes.
A G-protein.
It varies between sexes and races; men express more than women, and Europeans have a more active enzyme than Asians.
It is said to have a bioavailability of 1 or 100%.
By modifying particle size, using different compounds, and applying coatings like enteric coating.
They rotate polarized light equally but in opposite directions.
The process by which drugs absorbed from the gastrointestinal tract enter the hepatic portal circulation and are metabolized by the liver.
S-ketamine has greater affinity for the NMDA receptor, is twice as potent, and provides a more pleasant experience with quicker recovery.
A ligand binds to the extracellular site of a GPCR, causing a GTP molecule to bind to the intracellular α subunit of the G-protein trimer, leading to its separation and activation of various enzyme systems.
Because less creatinine is excreted and less is produced due to decreased muscle mass and physical activity.
Once bound only to GDP, the α subunit rejoins the βγ units to return to its resting state.
The glomerular filtration rate.
Only the L-isomer has beta-blocking activity.
Their effects are enhanced as they are usually highly protein bound.
Lactate-containing fluids, as lactate metabolism will be impaired.
It acts as an antagonist.
They alternate between ketone and enol states.
Acetylcholinesterase.
It inhibits the Na+/K+/2Cl- ATPase pump.
They are used as anaesthetics and sedatives.
Occurs when the action of one drug is blocked or reversed by another drug (i.e. 1 + 1 = 0). Example: morphine and naloxone.
Weak bases become more ionized (lipid insoluble) and are less well reabsorbed.
Factors include age, race, sex, disease state, and genetic polymorphism.
R (rectus) for clockwise and S (sinister) for anti-clockwise.
They are only minimally reabsorbed and readily excreted.
About 8 ml/min/1.73 m² per decade.
G<sub>s</sub> proteins, such as via stimulation of β adrenoceptors and glucagon receptors.
An autoimmune response generating antibodies against liver protein complexes.
They have differing anesthetic potency.
The groups are arranged on the same side of the double bond.
Adrenaline reduces the absorption of local anaesthetic by causing local vasoconstriction.
R-thalidomide is sedative, while S-thalidomide is teratogenic.
L-dopa is effective, while D-dopa causes neutropenia.
Probenecid can limit the secretion of penicillin by competing for the same carriers.
It reduces thyroxine production.
Acetylcholine binds to the nicotinic acetylcholine receptor, causing a conformational change that opens a pore for Na+ influx, leading to cell depolarization.
Drug concentration.
Administration of sodium bicarbonate in overdoses of aspirin and phenobarbital.
Gi proteins inhibit adenylate cyclase, causing a fall in cAMP.
Molecules that have the same molecular formula but whose atoms are arranged differently.
The α subunit has intrinsic GTPase activity, converting GTP into GDP.
By acting on numerous different systems within the body.
The patient should remain anaesthetised and ventilated until they can take good tidal volumes independently.
They induce hepatic enzymes, resulting in the accelerated breakdown of drugs metabolised by these enzymes.
Omeprazole inhibits hepatic enzymes, reducing the breakdown of drugs metabolised by these enzymes.
The ring is closed and lipid soluble.
Due to impaired coagulation and liver-induced thrombocytopenia.
Repeated exposure, female sex, obesity, and middle age.
Stereoisomers that possess more than one chiral centre and cannot form mirror images of each other.
Isomers where the carbon skeleton remains the same but the functional group varies in position.
A form of dynamic isomerism where two structural isomers exist in equilibrium.
It depends on the conditions of the surrounding environment, such as pH levels.
The ring is open and water soluble.
Up to a hundred G-proteins.
It blocks them.
The cardiac Na+/K+ ATPase pump.
Thalidomide, where one form has the desired effect and the other causes teratogenic side effects.
Isomers can be classified into structural isomers and stereoisomers, including chain isomers, positional isomers, functional isomers, and tautomers.
Glomerular filtration, active proximal tubular secretion, and passive distal tubular reabsorption.
Reduced renal mass, decreased number of glomeruli, and increased percentage of sclerotic glomeruli.
G<sub>q</sub> proteins, such as via stimulation of α<sub>1</sub> adrenoceptors and muscarinic acetylcholine receptors.
By the lack of muscle contractions in response to supramaximal nerve stimulation after an intubating dose of suxamethonium.
Variations in plasma cholinesterase enzymes lead to differences in the breakdown of suxamethonium, affecting its duration of action.
Carriers for acidic drugs (e.g., furosemide) and basic drugs (e.g., histamine).
It is carried by 4% of the Caucasian population.
It acts as an antagonist.
They neutralise gastric acids.
For example, ACE inhibitors are less effective in treating heart failure in black patients compared to white patients.
Toxicity, especially for drugs that are almost exclusively excreted by the kidneys.
S-warfarin is more potent with a half-life of 32 hours, while R-warfarin has a half-life of 54 hours.
Their metabolism is impaired, but effects are terminated by redistribution.
It describes differences in people's genotypes and the resulting variations in phenotypic expression of these genes.
nAChR as an agonist.
It acts as an antagonist.
FFP could theoretically provide normal plasma cholinesterase, but the risks cannot be justified; the patient should remain anaesthetised until the effects of suxamethonium wear off.
It is where the ligand binds.
Esmolol and remifentanil.
It blocks them.
They reduce noradrenaline reuptake.
Long acting (Phenobarbitone), Intermediate acting (Pentobarbitone), Short acting (Thiopentone).
Using dibucaine, which inhibits normal plasma cholinesterase but not an abnormal enzyme.
It acts as an agonist.
It acts as an antagonist.
It increases insulin production.
It is represented by the molecular formula with specific isopropyl groups attached to the phenol ring.
Opioid receptors as an agonist.
