Molecular Mechanisms of Drug Photodegradation and Photosensitization

Zaheer, Mohd. Rehan; Gupta, Anamika; Iqbal, Jawaid; Zia, Qamar; Ahmad, Akil; Roohi, .; Owais, Mohammad; Hashlamon, Ali; Setapar, Siti Hamidah Mohd; Ashraf, Ghulam Md; Aliev, Gjumrakch

doi:10.2174/1381612822666151209151408

Cited by 49 publications

(10 citation statements)

References 28 publications

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“…The chemical process of photodegradation generally consists in the oxidation of the dihydropyridine ring with the formation of the pyridine derivative. In some cases, the process leads to the formation of secondary photoproducts, mainly dependent on the functional groups present both on the phenyl and on the pyridine rings [8,9,10]. The mechanism starts with the transfer of the proton, probably to the solvent, from the excited single and it is favored, as in the case of nifedipine, by the presence of a nitro-group on the phenyl ring [11].…”

Section: Introductionmentioning

confidence: 99%

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1,4-Dihydropyridine Antihypertensive Drugs: Recent Advances in Photostabilization Strategies

2019

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The 1,4-dihydropyridine (DHP) drugs are nowadays the most used drugs in the treatment of hypertension. However, all the structures in this series present a significant sensitivity to light, leading to the complete loss of pharmacological activity. This degradation is particularly evident in aqueous solution, so much so that almost all DHP drugs on the market are formulated in solid preparations, especially tablets. The first and main process of photodegradation consists in the aromatization of the dihydropyridine ring, after which secondary processes can take place on the various substituents. A potential danger can result from the formation of single oxygen and superoxide species that can in turn trigger phototoxic reactions. Several strategies for the photostabilisation of DHP drugs have been proposed in recent years, in particular with the aim to formulate these drugs in liquid preparations, as well as to limit any toxicity problems related to light degradation. This review summarizes and describes the main aspects of the studies conducted in recent years to obtain photostable formulations of DHP drugs.

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Section: Introductionmentioning

confidence: 99%

“…Returning to the ground state, free radicals or photoproducts, potentially toxic to cell membranes or DNA, can be formed [20,21]. For some DHP drigs, data and results on phototoxicity have been reported [6,7,10].…”

Section: Introductionmentioning

confidence: 99%

1,4-Dihydropyridine Antihypertensive Drugs: Recent Advances in Photostabilization Strategies

2019

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“…Photoallergic reactions have much lower incidence (type IV immune response to light-activated compound is necessary), require smaller doses of drug, and manifest after a longer period of time – the symptoms usually become visible in 24–72 hours after exposure and include pruritic eczematous eruption, erythema, vesicles, lichenification, and scaling. The lesions can also spread to skin areas unexposed to sunlight 6–12…”

Section: Introductionmentioning

confidence: 99%

<p>Photosensitivity reactions in the elderly population: questionnaire-based survey and literature review</p>

Korzeniowska¹,

Cieślewicz²,

Chmara³

et al. 2019

TCRM

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PurposeOlder people are at risk of developing adverse drug reactions, including photosensitivity reactions. Therefore, the aim of the study was to assess the use of potentially photosensitizing medications and photoprotection in the elderly population.Patients and methodsThree hundred and fifty-six respondents (223 [63%] women and 133 [37%] men) aged ≥65 years filled in the original questionnaire concerning photosensitivity reactions to drugs. The diagnosis of drug-induced photosensitivity was based on medical history and clinical examination.Results and conclusionWe found that drugs potentially causing phototoxic/photoallergic reactions comprised more than one fifth of all drugs used by the participants. The most numerous group was patients treated with 3–5 drugs potentially causing phototoxic/photoallergic reactions simultaneously. Of all drugs, ketoprofen was found to cause the highest number of photosensitivity reactions. Cutaneous adverse reactions were also observed for hydrochlorothiazide, atorvastatin, simvastatin, telmisartan, and metformin. Moreover, it was found that the incidence of photosensitivity reactions can be significantly reduced by using proper photoprotection.

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“…One class of chemical structures that has not been much investigated however, is that of the antibiotics themselves. This is somewhat surprising, as phototoxicity has long been known to be one of the most troubling side-effects of antibiotics that are clinically administered for many infectious diseases 12 .…”

Section: Introductionmentioning

confidence: 99%

Antimicrobial Photodynamic Inactivation Mediated by Tetracyclines in Vitro and in Vivo: Photochemical Mechanisms and Potentiation by Potassium Iodide

Xuan

Huang

et al. 2018

Sci Rep

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Tetracyclines (including demeclocycline, DMCT, or doxycycline, DOTC) represent a class of dual-action antibacterial compounds, which can act as antibiotics in the dark, and also as photosensitizers under illumination with blue or UVA light. It is known that tetracyclines are taken up inside bacterial cells where they bind to ribosomes. In the present study, we investigated the photochemical mechanism: Type 1 (hydroxyl radicals); Type 2 (singlet oxygen); or Type 3 (oxygen independent). Moreover, we asked whether addition of potassium iodide (KI) could potentiate the aPDI activity of tetracyclines. High concentrations of KI (200–400 mM) strongly potentiated (up to 5 logs of extra killing) light-mediated killing of Gram-negative Escherichia coli or Gram-positive MRSA (although the latter was somewhat less susceptible). KI potentiation was still apparent after a washing step showing that the iodide could penetrate the E. coli cells where the tetracycline had bound. When cells were added to the tetracycline + KI mixture after light, killing was observed in the case of E. coli showing formation of free molecular iodine. Addition of azide quenched the formation of iodine but not hydrogen peroxide. DMCT but not DOTC iodinated tyrosine. Both E. coli and MRSA could be killed by tetracyclines plus light in the absence of oxygen and this killing was not quenched by azide. A mouse model of a superficial wound infection caused by bioluminescent E. coli could be treated by topical application of DMCT and blue light and bacterial regrowth did not occur owing to the continued anti biotic activity of the tetracycline.

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Molecular Mechanisms of Drug Photodegradation and Photosensitization

Cited by 49 publications

References 28 publications

1,4-Dihydropyridine Antihypertensive Drugs: Recent Advances in Photostabilization Strategies

1,4-Dihydropyridine Antihypertensive Drugs: Recent Advances in Photostabilization Strategies

<p>Photosensitivity reactions in the elderly population: questionnaire-based survey and literature review</p>

Antimicrobial Photodynamic Inactivation Mediated by Tetracyclines in Vitro and in Vivo: Photochemical Mechanisms and Potentiation by Potassium Iodide

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