Coleus

Coleus/Drug Interactions:

  • AbortifacientsAbortifacients: Coleus may theoretically have synergistic effects when taken with abortifacients, as one animal study showed that daily treatment with C. barbatus before embryo implantation in mice caused delayed fetal development and had an anti-implantation effect (1).
  • AnalgesicsAnalgesics: Some pain relievers may also increase the risk of bleeding if used with coleus. Examples include aspirin, ibuprofen (Motrin?, Advil?) and naproxen (Naprosyn?, Aleve?, Anaprox?) (5; 6).
  • AnestheticsAnesthetics: Theoretically, coleus may interact with anesthetics.
  • Antiasthma agentsAntiasthma agents: Forskolin has been studied for its effects in asthma. Theoretically, its use with bronchodilators or other asthma medications may result in additive effects. However, in one study, forskolin was shown to cause an apparent reversal of tachyphylaxis to the bronchodilator effects of salbutamol (43).
  • Anticoagulants and antiplateletsAnticoagulants and antiplatelets: Coleus is a potent inhibitor of platelet aggregation and its use with other antiplatelets or anticoagulants may increase the risk of bleeding (5; 6). Examples include warfarin (Coumadin?), heparin and clopidogrel (Plavix?). Some pain relievers, such as aspirin, ibuprofen (Motrin?, Advil?) and naproxen (Naprosyn?, Aleve, Anaprox?), may also increase the risk of bleeding if used with coleus. Drugs that may enhance the antiplatelet effect of forskolin include dipyridamole and dilazep.
  • Antidepressant agents, monoamine oxidase inhibitors (MAOIs)Antidepressants, selective serotonin reuptake inhibitors (SSRIs)Antidepressant agents, monoamine oxidase inhibitors (MAOIs), Antidepressants, selective serotonin reuptake inhibitors (SSRIs): Forskolin was shown to possess antidepressant activities, therefore, its use with other antidepressants may lead to additive effects (45).
  • Antidiabetic agentsAntidiabetic agents: Colenol, a compound isolated from coleus, stimulates insulin release, and its use with hypoglycemic agents or exogenous insulin may result in additive effects (39).
  • AntihistaminesAntihistamines: Forskolin caused a dose-dependent inhibition of antigen-induced histamine release from human basophil leukocytes, as well as a dose-dependent inhibition of histamine release from human lung mast cells (2). Its use with other antihistamines may result in additive effects. A dose of forskolin caused a concentration- related inhibition of immunoglobulin E (IgE)-mediated release of histamine and peptide leukotriene C4 (LTC4) from human basophils and lung mast cells (3).
  • AntihypertensivesAntihypertensives: Forskolin lowered blood pressure in dogs and cats and also in spontaneously hypertensive and renal hypertensive rats (38). When used with antihypertensives, it may result in additive effects.
  • Antineoplastic agentsAntineoplastic agents: One species of coleus, C. aromaticus (extract), has been shown to protect against cancer chemotherapy drug (cyclophosphamide and mitomycin-C) cell damage in mice. Lower doses were proven more effective than higher doses for this purpose.
  • Antiobesity agentsAntiobesity agents: Theoretically, coleus may have additive effects when taken with antiobesity agents because coleus has been shown to reduce body weight, food intake, and fact accumulation in ovariectomized rats (15). In addition, water-soluble extract of Coleus barbatus modulated weight gain, energy utilization and lipid metabolism in secondary biliary cirrhosis in an experimental study in young rats (7).
  • BronchodilatorsBronchodilators: Forskolin has been studied for its effects in asthma. Theoretically, its use with bronchodilators or other asthma medications may result in additive effects. However, in one study, forskolin was shown to cause an apparent reversal of tachyphylaxis to the bronchodilator effects of salbutamol (43).
  • Cardiac glycosidesCardiac glycosides: Lindner et al. established the positive inotropic activity of forskolin on the isolated guinea pig heart, on the isolated left atrium of the guinea pig heart and on the dog and cat heart in situ (38). Use with cardiac glycosides may result in additive effects.
  • Cardioactive agentsCardioactive agents: Forskolin has been shown to increase heart rate (38). Forskolin appeared to lower blood pressure in dogs and cats and also in spontaneously hypertensive and renal hypertensive rats (38).
  • Cardiovascular agentsCardiovascular agents: Forskolin has been shown to increase heart rate (38). Forskolin appeared to lower blood pressure in dogs and cats and also in spontaneously hypertensive and renal hypertensive rats (38).
  • Cytochrome P450 metabolized agentsCytochrome P450 metabolized agents: Cytochrome P450 is often mediated by nuclear receptor superfamily members designated PXR (pregnane X receptor). Activation of PXR represented the basis for several clinically important drug-drug interactions (10). Although PXR activation had undesirable effects in patients on combination therapy, it also mediated the hepatoprotective effects exhibited by some herbal remedies (10). It was shown that both forskolin and its nonadenyl cyclase-activating analog 1,9 dideoxyforskolin induced CYP3A gene expression in primary hepatocytes by functioning as agonists of PXR (9). The activation of PKA signaling potentiated PXR-mediated induction of CYP3A gene expression in cultured hepatocytes and increased the strength of PXR-coactivator protein-protein interaction in cell-based assays. Kinase assays showed that PXR could serve as a substrate for catalytically active PKA in vitro.
  • DecongestantsDecongestants: Forskolin was shown to increase heart rate, an action that was not inhibited by beta-blockers (38). Concomitant use of forskolin and decongestants theoretically may lead to adverse cardiovascular effects.
  • Gastrointestinal agents, miscellaneousGastrointestinal agents, miscellaneous: Coleus should be used cautiously when taken concurrently with agents that are dependent on pH and gastric action for breakdown and activation. The water extract of Coleus barbatus Benth produced increases in intestinal movement and decreases in gastric pH in an animal study (41).
  • Glaucoma agentsGlaucoma agents: Caprioli et al. demonstrated that topical forskolin significantly reduced intra-ocular pressure (IOP) in rabbits, monkeys and humans (20; 21). When used with other medications that decrease IOP, it may result in additive effects.
  • H2 blockersH2 blockers: Coleus should be used cautiously when taken concurrently with H2 blockers, as the water extract of Coleus barbatus Benth decreased gastric secretion in an animal study (41).
  • Heart rate regulating agentsHeart rate regulating agents: Forskolin was shown to increase heart rate, an action which was not inhibited by beta-blockers (38). Coleus may diminish effects of agents that reduce the heart rate.
  • InotropesInotropes: Lindner et al. established the positive inotropic activity of forskolin on the isolated guinea pig heart, on the isolated left atrium of the guinea pig heart, and on the dog and cat heart in situ (38). Use with other inotropic agents may result in additive effects.
  • Neurologic agentsNeurologic agents: Forskolin was shown to possess antidepressant activities, therefore, its use with other antidepressants may lead to additive effects (45).
  • Nonsteroidal antiinflammatory agents (NSAIDsNonsteroidal antiinflammatory agents (NSAIDs): Some pain relievers such as aspirin, ibuprofen, and naproxen may have an additive increase of the risk for bleeding if used with coleus (5; 6).
  • Proton pump inhibitors (PPIs)Proton pump inhibitors (PPIs): Coleus should be used cautiously when taken concurrently with proton pump inhibitors, as the water extract of Coleus barbatus Benth decreased gastric secretion in an animal study (41).
  • Thyroid hormonesThyroid hormones: Forskolin stimulates thyroid function, therefore, its use with thyroid medications may result in additive effects (44).
  • VasodilatorsVasodilators: Theoretically, coleus may have additive effects when taken with vasodilators, as forskolin may serve as a vasodilating substance in lower concentrations (46).

    • Coleus/Herb/Supplement Interactions:

  • AbortifacientsAbortifacients: Coleus may theoretically have synergistic effects when taken with abortifacients, as one animal study showed that daily treatment with C. barbatus before embryo implantation in mice caused delayed fetal development and had an anti-implantation effect (1).
  • AnalgesicsAnalgesics: Some pain relievers may also increase the risk of bleeding if used with coleus (5; 6).
  • AnestheticsAnesthetics: Theoretically, coleus may interact with anesthetics.
  • Anti inflammatory herbsAnti inflammatory herbs: Coleus may cause an increased risk of bleeding when taken with herbs that reduce inflammation (5; 6).
  • Antiasthma herbs and supplementsAntiasthma herbs and supplements: Forskolin has been studied for its effects in asthma. Theoretically, its use with bronchodilators or other asthma medications may result in additive effects. However, in one study, forskolin was shown to cause an apparent reversal of tachyphylaxis to the bronchodilator effects of salbutamol (43).
  • Anticoagulants and antiplateletsAnticoagulants and antiplatelets: Coleus is a potent inhibitor of platelet aggregation, and its use with other antiplatelet or anticoagulant supplements, such as Ginkgo biloba and garlic, may increase the risk of bleeding (5; 6).
  • Antidepressant agents, monoamine oxidase inhibitors (MAOIs)Antidepressants, selective serotonin reuptake inhibitors (SSRIs)Antidepressant agents, monoamine oxidase inhibitors (MAOIs), Antidepressants, selective serotonin reuptake inhibitors (SSRIs): Forskolin was shown to possess antidepressant activities; therefore, its use with other antidepressant herbs or supplements, such as St. John's wort, may lead to additive effects (45).
  • AntihistaminesAntihistamines: Forskolin caused a dose-dependent inhibition of antigen-induced histamine release from human basophil leukocytes, as well as a dose-dependent inhibition of histamine release from human lung mast cells (2). Its use with other antihistamines may result in additive effects.
  • AntineoplasticsAntineoplastics: One species of coleus, C. aromaticus (extract), has been shown to protect against cancer chemotherapy drug (cyclophosphamide and mitomycin-C) cell damage in mice. Lower doses were proven more effective than higher doses for this purpose.
  • Antiobesity herbs and supplementsAntiobesity herbs and supplements: Theoretically, coleus may have additive effects when taken with antiobesity agents because coleus has been shown to reduce body weight, food intake, and fact accumulation in ovariectomized rats (15). In addition, water-soluble extract of Coleus barbatus modulated weight gain, energy utilization and lipid metabolism in secondary biliary cirrhosis in an experimental study in young rats (7).
  • AntioxidantsAntioxidants: Coleus may have additive effects when taken with antioxidants, as coleus has exhibited antioxidant effects in vitro (4).
  • BronchodilatorsBronchodilators: Forskolin has been studied for its effects in asthma. Therefore, in theory, forskolin use with bronchodilators or other asthma herbs or supplements, such as hawthorn, may result in additive effects (43).
  • Cardiac glycosidesCardiac glycosides: Lindner et al. established the positive inotropic activity of forskolin on the isolated guinea pig heart, on the isolated left atrium of the guinea pig heart, and on the dog and cat heart in situ (38). Use with cardiac glycosides may result in additive effects.
  • Cardioactive herbsCardioactive herbs: Theoretically, concomitant use of forskolin with cardiac herbs or supplements, such as hawthorn, could potentiate the cardiac effects of those agents (12; 16).
  • Cardiovascular herbs and supplementsCardiovascular herbs and supplements: Forskolin has been shown to increase heart rate (38). Forskolin appeared to lower blood pressure in dogs and cats and also in spontaneously hypertensive and renal hypertensive rats (38).
  • Chronotropic herbsChronotropic herbs: Forskolin was shown to increase heart rate, an action that was not inhibited by beta-blockers (38). Coleus may diminish effects of agents that reduce the heart rate.
  • Cytochrome P450 metabolized herbs and supplementsCytochrome P450 metabolized herbs and supplements: Forskolin may induce CYP3A gene expression by functioning as agonists of the pregnane X receptor (PXR) (9; 10). Thus, coleus may interact with herbs or supplements metabolized by cytochrome P450.
  • Gastrointestinal herbs and supplementsGastrointestinal herbs and supplements: Coleus should be used cautiously when taken concurrently with agents that are dependent on pH and gastric action for breakdown and activation. The water extract of Coleus barbatus Benth produced increases in intestinal movement and decreases in gastric pH in an animal study (41).
  • HypoglycemicsHypoglycemics: Colenol, a compound isolated from coleus, stimulates insulin release, and its use with hypoglycemic herbs or supplements, such as bitter melon, may result in additive effects (39).
  • HypotensivesHypotensives: Forskolin lowers the blood pressure in dogs and cats and also in spontaneously hypertensive and renal hypertensive rats (38). When used with antihypertensives, it may result in additive effects.
  • Inotropic herbsInotropic herbs: Lindner et al established the positive inotropic activity of forskolin on the isolated guinea pig heart, on the isolated left atrium of the guinea pig heart, and on the dog and cat heart in situ (38). Use with other inotropic agents may result in additive effects.
  • Intraocular pressure altering herbsIntraocular pressure altering herbs: Caprioli et al. demonstrated that topical forskolin significantly reduces intra-ocular pressure (IOP) in rabbits, monkeys and humans (20; 21). When used with other medications that decrease IOP, it may result in additive effects.
  • Neurologic herbs and supplementsNeurologic herbs and supplements: Forskolin was shown to possess antidepressant activities, therefore, its use with other antidepressants may lead to additive effects (45).
  • Thyroid agentsThyroid agents: Forskolin stimulates thyroid function, therefore, its use with thyroid herbs or supplements, such as bladderwrack, may result in additive effects (44).
  • Vasodilator herbs and supplementsVasodilator herbs and supplements: Theoretically, coleus may have additive effects when taken with vasodilators, as forskolin may serve as a vasodilating substance in lower concentrations (46).

    • Coleus/Food Interactions:

  • Acidic foods/fluidsAcidic foods/fluids: Theoretically, coleus may interact with these foods and fluids. Coleus barbatus Benth has produced an increase in intestinal movement and a decrease in gastric pH in rats (41).

    • Coleus/Lab Interactions:

  • Blood pressureBlood pressure: Forskolin lowers the blood pressure in dogs and cats and also in spontaneously hypertensive and renal hypertensive rats (38).
  • GlucoseGlucose: Colenol, a compound isolated from coleus, stimulates glucose release (39).
  • Heart rateHeart rate: Studying the hemodynamic effects of forskolin in patients with dilated cardiomyopathy, Schlepper et al. found, using a dosage of 4mcg/kg per minute, an increase in dP/dtmax and a rise in heart rate (30). This tachycardic effect was not blocked by beta-blockers (38).
  • HistamineHistamine: Forskolin caused a dose-dependent inhibition of antigen-induced histamine release from human basophil leukocytes, as well as a dose-dependent inhibition of histamine release from human lung mast cells (2).
  • InsulinInsulin: Colenol, a compound isolated from coleus, stimulates insulin release and could theoretically lead to increased insulin concentrations (39).
  • Lutenizing hormone (LH)Lutenizing hormone (LH): Forskolin has been reported to stimulate LH release (47).
  • PT/INRPT/INR: Coleus is a potent platelet aggregation inhibitor and thereby alters PT and/or INR (5; 6). However, there is a lack of documented reports in the available literature confirming this theoretical interaction.
  • Thyroid hormonesThyroid hormones: Forskolin stimulates thyroid function and therefore may alter TSH, T3, or T4 concentrations (44). However, there is a lack of documented reports in the available literature.