Medical<unk>  is used in: * Bronchopulmonary dysplasia in premature infants for both prevention and treatment. It may improve weight gain during therapy and reduce the incidence of cerebral palsy as well as reduce language and cognitive delay. On the other hand, subtle long-term side effects are possible. * Apnea of prematurity as a primary treatment, but not prevention. * Orthostatic hypotension treatment. * Some people use<unk> -containing beverages such as coffee or tea to try to treat their asthma. Evidence to support this practice, however, is poor. It appears that<unk>  in low doses improves airway function in people with asthma, increasing forced expiratory volume (FEV1) by 5% to 18%, with this effect lasting for up to four hours. *The addition of<unk>  (100–130 mg) to commonly prescribed pain relievers such as paracetamol or ibuprofen modestly improves the proportion of people who achieve pain relief. * Consumption of<unk>  after abdominal surgery shortens the time to recovery of normal bowel function and shortens length of hospital stay. Enhancing performance Cognitive<unk>  is a central nervous system stimulant that may reduce fatigue and drowsiness. At normal doses,<unk>  has variable effects on learning and memory, but it generally improves reaction time, wakefulness, concentration, and motor coordination. The amount of<unk>  needed to produce these effects varies from person to person, depending on body size and degree of tolerance. The desired effects arise approximately one hour after consumption, and the desired effects of a moderate dose usually subside after about three or four hours.<unk> <unk> n delay or prevent sleep and improves task performance during sleep deprivation. Shift workers who use<unk>  make fewer mistakes that could result from drowsiness.<unk>  in a dose dependent manner increases alertness in both fatigued and normal individuals. A systematic review and meta-analysis from 2014 found that concurrent<unk>  and -theanine use has synergistic psychoactive effects that promote alertness, attention, and task switching; these effects are most pronounced during the first hour post-dose. Physical<unk>  is a proven ergogenic aid in humans.<unk>  improves athletic performance in aerobic (especially endurance sports) and anaerobic conditions. Moderate doses of<unk>  (around 5 mg/kg)<unk> n improve sprint performance, cycling and running time trial performance, endurance (i.e., it delays the onset of muscle fatigue and central fatigue), and cycling power output.<unk>  increases basal metabolic rate in adults.<unk>  ingestion prior to aerobic exercise increases fat oxidation, particularly in persons with low physical fitness.<unk>  improves muscular strength and power, and may enhance muscular endurance.<unk>  also enhances performance on anaerobic tests.<unk>  consumption before constant load exercise is associated with reduced perceived exertion. While this effect is not present during exercise-to-exhaustion exercise, performance is significantly enhanced. This is congruent with<unk>  reducing perceived exertion, because exercise-to-exhaustion should end at the same point of fatigue.<unk>  also improves power output and reduces time to completion in aerobic time trials, an effect positively (but not exclusively) associated with longer duration exercise. Specific populations Adults For the general population of healthy adults, Health<unk> nada advises a daily intake of no more than 400 mg. This limit was found to be safe by a 2017 systematic review on<unk>  toxicology. Children In healthy children, moderate<unk>  intake under 400 mg produces effects that are "modest and typically innocuous". As early as 6 months old, infants<unk> n metabolize<unk>  at the same rate as that of adults. Higher doses of<unk>  (>400 mg)<unk> n<unk> use physiological, psychological and behavioral harm, particularly for children with psychiatric or<unk> rdiac conditions. There is no evidence that coffee stunts a child's growth. The American Academy of Pediatrics recommends that<unk>  consumption is not appropriate for children and adolescents and should be avoided. This recommendation is based on a clinical report released by American Academy of Pediatrics in 2011 with a review of 45 publications from 1994 to 2011 and includes inputs from various stakeholders (Pediatricians, Committee on nutrition,<unk> nadian Pediatric Society, Centers for Disease Control & Prevention, Food and Drug Administration, Sports Medicine & Fitness committee, National Federations of High School Associations). For children age 12 and under, Health<unk> nada recommends a maximum daily<unk>  intake of no more than 2.5 milligrams per kilogram of body weight. Based on average body weights of children, this translates to the following age-based intake limits: Age range Maximum recommended daily<unk>  intake 4–6 45 mg (slightly more than in 355 ml (12 fl. oz) of a typical<unk> ted soft drink) 7–9 62.5 mg 10–12 85 mg (about cup of coffee) Adolescents Health<unk> nada has not developed advice for adolescents because of insufficient data. However, they suggest that daily<unk>  intake for this age group be no more than 2.5 mg/kg body weight. This is because the maximum adult<unk>  dose may not be appropriate for light-weight adolescents or for younger adolescents who are still growing. The daily dose of 2.5 mg/kg body weight would not<unk> use adverse health effects in the majority of adolescent<unk>  consumers. This is a conservative suggestion since older and heavier-weight adolescents may be able to consume adult doses of<unk>  without suffering adverse effects. Pregnancy and breastfeeding The metabolism of<unk>  is reduced in pregnancy, especially in the third trimester, and the half-life of<unk>  during pregnancy<unk> n be increased up to 15 hours (as compared to 2.5 to 4.5 hours in non-pregnant adults). Current evidence regarding the effects of<unk>  on pregnancy and for breastfeeding are inconclusive. There is limited primary and secondary advice for, or against,<unk>  use during pregnancy and its effects on the fetus or newborn. The UK Food Standards Agency has recommended that pregnant women should limit their<unk>  intake, out of prudence, to less than 200 mg of<unk>  a day – the equivalent of two cups of instant coffee, or one and a half to two cups of fresh coffee. The American Congress of Obstetricians and Gynecologists (ACOG) concluded in 2010 that<unk>  consumption is safe up to 200 mg per day in pregnant women. For women who breastfeed, are pregnant, or may become pregnant, Health<unk> nada recommends a maximum daily<unk>  intake of no more than 300 mg, or a little over two 8 oz (237 mL) cups of coffee. A 2017 systematic review on<unk>  toxicology found evidence supporting that<unk>  consumption up to 300 mg/day for pregnant women is generally not associated with adverse reproductive or developmental effect. There are conflicting reports in the scientific literature about<unk>  use during pregnancy. A 2011 review found that<unk>  during pregnancy does not appear to increase the risk of congenital malformations, miscarriage or growth retardation even when consumed in moderate to high amounts. Other reviews, however, concluded that there is some evidence that higher<unk>  intake by pregnant women may be associated with a higher risk of giving birth to a low birth weight baby, and may be associated with a higher risk of pregnancy loss. A systematic review, analyzing the results of observational studies, suggests that women who consume large amounts of<unk>  (greater than 300 mg/day) prior to becoming pregnant may have a higher risk of experiencing pregnancy loss.
Caffeine
Methacholine
Betahistine
Nicotine
Phenylpropanolamine
Molsidomine
Piperoxan
Codeine