II. Types: General
- Pharmacokinetic (most common)
- Two drugs compete for the same mechanism of absorption, distribution, metabolism or excretion (ADME)
- Results in a change in one or both drugs concentration at the site of their action when both agents are taken
- Typically involves Cytochrome P450, UGT, P-Glycoprotein or OATP
- Often drug dosage changes and monitoring are sufficient for low to moderate risk interactions
- Pharmacodynamic
- One drug directly blocks or exacerbates another drugs activity without modifying drug concentrations
- Offending drug, typically must be stopped (drug dosage modifications typically do not resolve interaction)
III. Types: Pharmacokinetic Interaction Mechanisms
- Altered Drug Absorption
- Drug absorption is inhibited by a second agent
- Gastrointestinal absorption may be affected by altered pH (e.g. Antacids), ion or chemical binding (e.g. Doxycycline) or gi motility
- Altered Drug Metabolism
- See Drug Metabolism
- Cytochrome P450 metabolism my be inhibited (increasing Drug Activity) or induced (decreasing Drug Activity)
- Plasma Protein Binding Competition
- Two drugs may compete for plasma Protein binding sites, with one with lower affinity displaced, resulting in increased serum drug levels
- Altered Drug Excretion
- Renal excretion may be decreased for a drug that competes for specific carrier Protein facilitated transport resulting in increased drug levels
IV. Types: Drug Interactions
- Additive Drug Interactions (1 + 1 = 2)
- Effect is equal to what would be expected from the combination of the 2 individual drugs
- Synergistic Drug Interactions (1 + 1 = 3)
- Effect is greater than what would be expected from the additive effects of the 2 individual drugs
- Potentiated Drug Interactions (0 + 1 = 2)
- Drug which normally does not have clinical effect, potentiates a second drug to greater effect
-
Antagonistic Drug Interactions (1 + 1 = 0)
- One drug inhibits the effect of a second drug
V. Causes: Food Interactions
- See Antibiotic Food Interactions
- See Grapefruit Interactions
VI. Causes: Common Serious Drug-Drug Interactions
- Drugs with numerous interactions
- Specific important drug-Drug Interactions
- Phosphodiesterase Inhibitor (e.g. Viagra) and Nitroglycerin (Hypotension)
- Beta Blockers and Clonidine (Hypertensive Crisis)
- ACE Inhibitors and Potassium supplements, Potassium-Sparing Diuretics or Septra (Hyperkalemia)
- Drug-Induced Syndromes (exacerbated by combinations of agents)
VII. References
- Olson (2020) Pharmacology, Medmaster, Miami, p. 1-12
- Asher (2017) Am Fam Physician 96(2): 101-7 [PubMed]
Images: Related links to external sites (from Bing)
Related Studies
| Definition (CSP) | physical chemical interaction between nutrients, or between nutrients and other components of the diet or other compounds, including desirable or undesirable results; nutrients are substances that can be metabolized by an organism to give energy and build tissue; for the concept of nutrients interacting with drugs use NUTRIENT DRUG INTERACTION. |
| Concepts | Natural Phenomenon or Process (T070) |
| MSH | D018565 |
| English | Food Interaction, Interaction, Food, Interactions, Food, nutrient interaction, Food interaction, food interactions, interactions nutrient, foods interactions, interaction food, food interaction, Food Interactions |
| Italian | Interazione con il cibo, Interazioni alimentari |
| Japanese | 食物との相互作用, ｼｮｸﾓﾂﾄﾉｿｳｺﾞｻﾖｳ |
| Portuguese | Interações de Alimentos, Interacção com alimentos |
| Spanish | Interacciones de Alimento, Interacción con alimentos |
| French | Interactions alimentaires, Interactions des aliments, Interaction avec l'alimentation |
| German | Nahrungsmittelinteraktionen, Wechselwirkung mit Nahrungsmitteln |
| Czech | Potravinová interakce, interakce potravin, ovlivnění účinku léků potravou |
| Hungarian | Étel kölcsönhatás |
| Dutch | voedselinteractie |
Ontology: Food-Drug Interactions (C0242785)
| Definition (MSH) | The pharmacological result, either desirable or undesirable, of drugs interacting with components of the diet. (From Stedman, 25th ed) |
| Definition (CSP) | either desirable or undesirable pharmacological result of drugs interacting with nutrients; used for both drugs of abuse and pharmaceuticals interacting with nutrients. |
| Concepts | Disease or Syndrome (T047) |
| MSH | D018565 |
| SnomedCT | 95907004 |
| English | Drug Food Interactions, Drug-Food Interaction, Drug-Food Interactions, Food Drug Interactions, Food-Drug Interaction, Food-Drug Interactions, Interaction, Drug-Food, Interaction, Food-Drug, Interactions, Drug-Food, Interactions, Food-Drug, nutrient drug interaction, DRUG - FOOD INTERACTION, Drug - food interaction, drug interaction with food, drug-food interaction, drugs foods interactions, drugs interaction nutrient, drug-food interactions, drugs food interaction, drug interactions nutrient, drugs food interactions, interaction drug food, drug food interactions, drug interaction food, drug nutrient interaction, food-drug interaction, food-drug interactions, drugs interaction nutrients, drug food interaction, drug foods interaction, food drug interaction, interaction drug nutrient, drugs interactions nutrient, food drug interactions, Drug interaction with food (finding), Drug interaction with food (disorder), Drug-nutrient interactions, Drug interaction with food, Food interaction with drug |
| Dutch | geneesmiddel-voedsel interactie, Interactie, voedsel-geneesmiddel-, Voedsel-geneesmiddelinteractie |
| French | Interaction médicament-aliment, Interactions aliment-médicament, Interactions médicaments-aliments, Interactions aliments-médicaments, INTERACTION MEDICAMENT/ALIMENT, Interactions médicament-aliment |
| German | Wechselwirkung von Medikamenten und Nahrungsmittel, Arzneimittel-Nahrungsmittel-Interaktionen, Nahrungsmittel-Arzneimittel-Interaktionen |
| Italian | Interazione farmaco-cibo, Interazioni farmaci-alimenti |
| Portuguese | Interacção fármaco-alimentos, INTERACAO MEDICAMENTO-ALIMENTO, Interações Alimento-Droga |
| Spanish | Interacción de fármacos con alimentos, interacción de un fármaco con los alimentos, interacción de un fármaco con los alimentos (trastorno), interacción de fármaco con alimentos (hallazgo), interacción de los alimentos con una droga, interacción de fármaco con alimentos, Interacciones Alimento-Droga |
| Japanese | 薬物・食物相互作用, ﾔｸﾌﾞﾂｼｮｸﾓﾂｿｳｺﾞｻﾖｳ, 食品医薬品相互作用, 食品相互作用, 薬物食品相互作用, 食品薬物相互作用, 医薬品食品相互作用 |
| Swedish | Kost-läkemedelsinteraktioner |
| Czech | interakce mezi potravou a léky, Interakce léku s potravinou, vzájemné působení léků s potravinami |
| Finnish | Ruoka-lääkeaineinteraktiot |
| Russian | PISHCHEVOI PRODUKT-LEKARSTVO, VZAIMODEISTVIE, LEKARSTVENNO-PISHCHEVYE VZAIMODEISTVIIA, PISHCHA-LEKARSTVO, VZAIMODEISTVIIA, PISHCHEVYKH KOMPONENTOV VZAIMODEISTVIIA, ЛЕКАРСТВЕННО-ПИЩЕВЫЕ ВЗАИМОДЕЙСТВИЯ, ПИЩА-ЛЕКАРСТВО, ВЗАИМОДЕЙСТВИЯ, ПИЩЕВОЙ ПРОДУКТ-ЛЕКАРСТВО, ВЗАИМОДЕЙСТВИЕ, ПИЩЕВЫХ КОМПОНЕНТОВ ВЗАИМОДЕЙСТВИЯ |
| Polish | Interakcja żywność-leki |
| Hungarian | Gyógyszer - étel kölcsönhatás |
Ontology: Drug Interactions (C0687133)
| Definition (NCI_NCI-GLOSS) | A change in the way a drug acts in the body when taken with certain other drugs, herbals, or foods, or when taken with certain medical conditions. Drug interactions may cause the drug to be more or less effective, or cause effects on the body that are not expected. |
| Definition (NCI) | Alteration of the disposition and/or effect of a drug, owing to the presence of another factor such as a second drug, or food. |
| Definition (MSH) | The action of a drug that may affect the activity, metabolism, or toxicity of another drug. |
| Definition (PSY) | Chemical and/or pharmacological reactions of drugs in combination, including agonistic and antagonistic interactions. |
| Definition (CSP) | physical chemical interaction between drugs and other compounds, including other drugs, particularly in biological systems. |
| Concepts | Molecular Function (T044) |
| MSH | D004347 |
| SnomedCT | 404204005, 79899007, 277359009 |
| English | Drug Interactions, Interaction, Drug, Interactions, Drug, Interaction, Drug Interaction, Drug interaction (NOS), Drug interaction NOS, Interaction drug (NOS), Interactions, drug drug interaction, drug-drug interaction, drug interaction with, drug interactions, drug interaction, Drug interaction with drug (finding), Drug interaction with drug (disorder), Drug interaction (finding), Drug interaction (disorder), drug interaction (treatment), Drug interactions, INTERACTION, Drug interaction, Drug drug interaction, Drug interaction with drug |
| Italian | Interazione farmacologica, Interazioni, Interazione, Interazione farmacologica (NAS), Interazione farmacologica NAS, Interazioni farmacologiche |
| Dutch | interactie geneesmiddel (NAO), interactie, geneesmiddeleninteractie NAO, geneesmiddelinteractie (NAO), geneesmiddelinteractie, interacties, Geneesmiddeleninteractie, Interactie, geneesmiddelen- |
| French | Interaction médicamenteuse SAI, Interaction, Interaction médicamenteuse, Interactions, Interactions médicamenteuses |
| German | Wechselwirkung, Arzneimittelwechselwirkung NNB, Wechselwirkung, Arzneimittel (NNB), Arzneimittelwechselwirkung (NNB), Arzneimittelwechselwirkung, Wechselwirkungen, Arzneimittelwechselwirkungen |
| Portuguese | Interacção, Interacção farmacológica NE, Interacção de fármacos NE, Interacção medicamentosa, Interacções, Interações de Medicamentos |
| Spanish | Interacción medicamentosa NEOM, Interacción medicamentosa (NEOM), Interacción, interacción farmacológica (trastorno), interacción farmacológica (hallazgo), interacción medicamentosa (hallazgo), interacción medicamentosa (trastorno), interacción fármaco-fármaco, interacción farmacológica, Interacciones, Interacción medicamentosa, interacción medicamentosa, Interacciones de Drogas |
| Japanese | 薬物相互作用ＮＯＳ, 薬物相互作用, 薬物相互作用（ＮＯＳ）, 相互作用, ｿｳｺﾞｻﾖｳ, ﾔｸﾌﾞﾂｿｳｺﾞｻﾖｳNOS, ﾔｸﾌﾞﾂｿｳｺﾞｻﾖｳ |
| Swedish | Läkemedelsinteraktioner |
| Finnish | Lääkkeiden interaktiot |
| Russian | LEKARSTV VZAIMODEISTVIIA, ЛЕКАРСТВ ВЗАИМОДЕЙСТВИЯ |
| Czech | Léková interakce NOS, Interakce, Vzájemná působení, Léková interakce, Léková interakce (NOS), léky - interakce, lékové interakce |
| Croatian | LIJEKOVI, INTERAKCIJE |
| Polish | Interakcja leków, Interakcja substancji chemicznych |
| Hungarian | Gyógyszerkölcsönhatás (k.m.n.), Gyógyszerkölcsönhatás k.m.n., Kölcsönhatás, Gyógyszerkölcsönhatás, Kölcsönhatások, Gyógyszer kölcsönhatás (k.m.n.) |
