A caffeine patch is a type of a transdermal patch designed to deliver caffeine to the body through the skin. The concept is similar to that of a nicotine patch. [1] [2] [3] [4] [5]
Caffeine is a stimulant of the methylxanthine class. It is mainly used recreationally to increase alertness in beverage form. Caffeine's structure is similar to that of adenosine, a naturally occurring molecule that has many physiologic effects on the body. [6] Due to caffeine's popularity as the world's most consumed drug, it has been altered to several forms for use such as beverages, pills, and patches. [7]
When a person is awake and alert, their brain has low levels of adenosine built up. The longer they stay awake, the more adenosine builds up and makes them feel sleepy. This happens because adenosine attaches to certain cell receptors in the brain that cause drowsiness.
When a person consumes caffeine, it blocks (antagonizes) the adenosine from attaching to those receptors, and as a result, they feel less sleepy and more alert. Caffeine's effect is only temporary and can help maintain or restore alertness.
Caffeine can cross the blood-brain barrier, which means it can enter the brain and affect the nervous system directly. Caffeine is particularly good at blocking the A2A Adenosine receptor. Blocking the A2A receptor is thought to be responsible for promoting wakefulness.
Caffeine also affects other systems in the body such as heart rate, breathing rate, and blood vessels. It can also cause the release of neurotransmitters like monoamines and acetylcholine, which contribute to its stimulating effects.
Apart from blocking adenosine receptors, caffeine also blocks the inositol trisphosphate receptor 1, the ionotropic glycine receptor, and activates ryanodine receptors. Together these actions contribute to the stimulating effects of caffeine felt after consuming it.
Caffeine blocks an enzyme called phosphodiesterase, which leads to an intracellular increase in a molecule called cyclic AMP (cAMP). This increase activates another enzyme called protein kinase A, which can reduce inflammation. Caffeine also has an effect on another chemical called acetylcholine, by slowing down the activity of an enzyme that breaks it down in the body, cholinesterase thus leading to an increase in acetylcholine levels. [6]
Several studies measured the total amount of caffeine penetrated via patch on different anatomical sites and were ranked as follows:
Researchers studied how skin aging affects the absorption of caffeine by the body. They found that older subjects absorbed more caffeine than younger subjects due to reduced sebaceous gland activity and skin lipid content. However, changes in skin hydration and corneocyte size could also play a role. [9]
A 2010 study showed that caffeine residue loosely sits on the skin and is not quickly absorbed. People who wash the skin around their caffeine patch showed significantly lower levels of caffeine. Therefore, for maximum effects it is suggested to avoid washing the area where the patch is placed. [10]
Several studies have looked at the effect hair has on skin absorption. It has been demonstrated that hair follicles are considered a weak spot in the protective barrier against certain types of drugs. This suggests that increasing the number of hair follicles allows for a faster delivery of topically applied solutions. [11] [12]
Caffeine is a first line treatment for neonatal apnea due to its metabolites' (theophyllines) effects on the lungs and breathing rate. Oral administration of medication in neonates is difficult for several reasons. Poor swallowing and GI compromise often lead to unpredictable and erratic dosing. This makes transdermal delivery of medications an ideal and promising choice. Studies have shown that caffeine applied twice daily in gel formulation in neonates is sufficient to maintain therapeutic levels of caffeine while avoiding oral dosing complications. [13] [14]
Cellulite is a complex skin disorder involving multiple factors such as microcirculatory, lymphatic drainage, extracellular matrix, and excess fat accumulation. Caffeine has been hypothesized to help with this as it stimulates lipolysis (fat metabolism) and lymphatic drainage thus helping remove accumulated fat and toxins. Caffeine also increases blood flow through the microcirculation further assisting in removing toxins and waste products. Studies using caffeine patches at various concentrations show promising results in the treatment of cellulite. [6]
Caffeine has also been shown to reduce swelling around the eyes although this use is usually via a gel formula of caffeine.
Caffeine exerts antioxidant effects, prevents UV skin damage, stimulates hair growth, and inhibits hair loss. These effects have made it an area of interest in adding caffeine to sunscreens, shampoos, and conditioners. [6]
Transdermal absorption of caffeine is difficult because of its hydrophilic structure. Current promising research is underway utilizing hydrogel microneedles in an attempt to bypass the obstacles in skin permeation. [9]
Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class. It is mainly used as a eugeroic (wakefulness promoter) or as a mild cognitive enhancer to increase alertness and attentional performance. Caffeine acts by blocking binding of adenosine to the adenosine A1 receptor, which enhances release of the neurotransmitter acetylcholine. Caffeine has a three-dimensional structure similar to that of adenosine, which allows it to bind and block its receptors. Caffeine also increases cyclic AMP levels through nonselective inhibition of phosphodiesterase.
Stimulants are a class of drugs that increase the activity of the brain and the spinal cord. They are used for various purposes, such as enhancing alertness, attention, motivation, cognition, mood, and physical performance. Some of the most common stimulants are caffeine, nicotine, amphetamines, cocaine, and modafinil.
Adenosine (symbol A) is an organic compound that occurs widely in nature in the form of diverse derivatives. The molecule consists of an adenine attached to a ribose via a β-N9-glycosidic bond. Adenosine is one of the four nucleoside building blocks of RNA (and its derivative deoxyadenosine is a building block of DNA), which are essential for all life on Earth. Its derivatives include the energy carriers adenosine mono-, di-, and triphosphate, also known as AMP/ADP/ATP. Cyclic adenosine monophosphate (cAMP) is pervasive in signal transduction. Adenosine is used as an intravenous medication for some cardiac arrhythmias.
Dopamine receptors are a class of G protein-coupled receptors that are prominent in the vertebrate central nervous system (CNS). Dopamine receptors activate different effectors through not only G-protein coupling, but also signaling through different protein interactions. The neurotransmitter dopamine is the primary endogenous ligand for dopamine receptors.
The adenosine receptors (or P1 receptors) are a class of purinergic G protein-coupled receptors with adenosine as the endogenous ligand. There are four known types of adenosine receptors in humans: A1, A2A, A2B and A3; each is encoded by a different gene.
Sleep inertia is a physiological state of impaired cognitive and sensory-motor performance that is present immediately after awakening. It persists during the transition of sleep to wakefulness, where an individual will experience feelings of drowsiness, disorientation and a decline in motor dexterity. Impairment from sleep inertia may take several hours to dissipate. In the majority of cases, morning sleep inertia is experienced for 15 to 30 minutes after waking.
Caffeine dependence is a condition characterized by a set of criteria including tolerance, withdrawal symptoms, persistent desire or unsuccessful efforts to control use, and continued use despite knowledge of adverse consequences attributed to caffeine. It can appear in physical dependence or psychological dependence, or both. Caffeine is one of the most common additives in many consumer products, including pills and beverages such as caffeinated alcoholic beverages, energy drinks, pain reliever medications, and colas. Caffeine is found naturally in plants such as coffee and tea and other plants. Studies have found that 89 percent of adults in the U.S. consume on average 200 mg of caffeine daily. One area of concern that has been presented is the relationship between pregnancy and caffeine consumption. When looking at the relationship between pregnancy and caffeine, caffeine doses of 100 mg appeared to result in smaller size at birth. When looking at birth weight however, there was no significant difference when there was a large amount of caffeine consumed.
Paraxanthine, also known as 1,7-dimethylxanthine, is a metabolite of theophylline and theobromine, two well-known stimulants found in coffee, tea, and chocolate mainly in the form of caffeine. It is a member of the xanthine family of alkaloids, which includes theophylline, theobromine and caffeine.
An analeptic, in medicine, is a central nervous system stimulant. The term "analeptic" typically refers to respiratory stimulants. Analeptics are central nervous system (CNS) stimulants that include a wide variety of medications used to treat depression, attention deficit hyperactivity disorder (ADHD), and respiratory depression. Analeptics can also be used as convulsants, with low doses causing patients to experience heightened awareness, restlessness, and rapid breathing. The primary medical use of these drugs is as an anesthetic recovery tool or to treat emergency respiratory depression. Other drugs of this category are prethcamide, pentylenetetrazole, and nikethamide. Nikethamide is now withdrawn due to risk of convulsions. Analeptics have recently been used to better understand the treatment of a barbiturate overdose. Through the use of agents, researchers were able to treat obtundation and respiratory depression.
The adenosine A1 receptor (A1AR) is one member of the adenosine receptor group of G protein-coupled receptors with adenosine as endogenous ligand.
An anxiogenic or panicogenic substance is one that causes anxiety. This effect is in contrast to anxiolytic agents, which inhibits anxiety. Together these categories of psychoactive compounds may be referred to as anxiotropic compounds.
A heteromer is something that consists of different parts; the antonym of homomeric. Examples are:
The adenosine A2A receptor, also known as ADORA2A, is an adenosine receptor, and also denotes the human gene encoding it.
SCH-58261 is a drug which acts as a potent and selective antagonist for the adenosine receptor A2A, with more than 50x selectivity for A2A over other adenosine receptors. It has been used to investigate the mechanism of action of caffeine, which is a mixed A1 / A2A antagonist, and has shown that the A2A receptor is primarily responsible for the stimulant and ergogenic effects of caffeine, but blockade of both A1 and A2A receptors is required to accurately replicate caffeine's effects in animals. SCH-58261 has also shown antidepressant, nootropic and neuroprotective effects in a variety of animal models, and has been investigated as a possible treatment for Parkinson's disease.
Regadenoson, sold under the brand name Lexiscan among others, is an A2A adenosine receptor agonist that is a coronary vasodilator that is commonly used in pharmacologic stress testing. It produces hyperemia quickly and maintains it for a duration that is useful for radionuclide myocardial perfusion imaging. The selective nature of the drug makes it preferable to other stress agents such as adenosine, which are less selective and therefore cause more side-effects.
CGS-15943 is a drug which acts as a potent and reasonably selective antagonist for the adenosine receptors A1 and A2A, having a Ki of 3.3nM at A2A and 21nM at A1. It was one of the first adenosine receptor antagonists discovered that is not a xanthine derivative, instead being a triazoloquinazoline. Consequently, CGS-15943 has the advantage over most xanthine derivatives that it is not a phosphodiesterase inhibitor, and so has more a specific pharmacological effects profile. It produces similar effects to caffeine in animal studies, though with higher potency.
Theacrine, also known as 1,3,7,9-tetramethyluric acid, is a purine alkaloid found in Cupuaçu and in a Chinese tea known as kucha. It shows anti-inflammatory and analgesic effects and appears to affect adenosine signalling in a manner similar to caffeine. In kucha leaves, theacrine is synthesized from caffeine in what is thought to be a three-step pathway. Theacrine and caffeine are structurally similar.
Purinergic signalling is a form of extracellular signalling mediated by purine nucleotides and nucleosides such as adenosine and ATP. It involves the activation of purinergic receptors in the cell and/or in nearby cells, thereby regulating cellular functions.
Caffeine-induced anxiety disorder is a subclass of the DSM-5 diagnosis of substance/medication-induced anxiety disorder.
Adenosine A2A receptor antagonists are a class of drugs that blocks adenosine at the adenosine A2A receptor. Notable adenosine A2A receptor antagonists include caffeine, theophylline and istradefylline.
{{cite web}}
: Missing or empty |title=
(help)