black tea


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Related to black tea: Oolong tea

black tea

(blak tee) ,

Camellia sinensis

(trade name),

English tea

(trade name),

Theaflavin

(trade name)

Classification

Therapeutic: central nervous system stimulants
Mental alertness HeadacheWeight lossMyocardial infarction and atherosclerosis prevention

Action

Black tea contains caffeine (2–4%) a methylxanthine that stimulates the CNS through adenosine receptor blockade and phosphodiesterase inhibition, relaxes smooth muscle in the airways, stimulates the heart and has diuretic effects. Theaflavins and tannins present in black tea are responsible for antioxidant properties.

Therapeutic effects

CNS stimulation.
Diuresis.
Elevated heart rate and BP.

Pharmacokinetics

Absorption: Unknown.
Distribution: Unknown.
Metabolism and Excretion: Unknown.
Half-life: Unknown.

Time/action profile

ROUTEONSETPEAKDURATION
POunknownunknownunknown

Contraindications/Precautions

Contraindicated in: Allergy or hypersensitivity to caffeine or tannin; Obstetric: Pregnancy and lactation (in high doses due to caffeine content).
Use Cautiously in: Cardiac arrhythmias; Diabetes; Peptic ulcer disease; Osteoporosis (caffeine increases urinary calcium excretion); Iron deficiency anemia (may worsen); Pediatric: Safety and efficacy has not been established in children.

Adverse Reactions/Side Effects

Cardiovascular

  • arrhythmia
  • hypertension
  • tachycardia

Central nervous system

  • insomnia
  • tremor

Dermatologic

  • rash
  • hives

Endocrinologic

  • hyperglycemia

Fluid and Electrolyte

  • hypokalemia
  • hyponatremia

Gastrointestinal

  • constipation
  • increased stomach acid

Hematologic

  • iron deficiency
  • microcytic anemia

Genitourinary

  • diuresis
  • increased urine sodium, potassium, and calcium levels

Musculoskeletal

  • rhabdomyolysis (high doses)

Interactions

Cimetidine, disulfiram, fluvoxamine, phenylpropanolamine, fluoroquinolones, and estrogens can ↓ caffeine clearance and ↑ adverse effects. Caffeine can inhibit dipyridamole -induced vasodilation.Abrupt withdrawal of caffeine can ↑ lithium levels.Additive stimulatory effects with CNS stimulants.Caffeine can ↑ theophylline levels.May ↑ heart rate and BP when used with bitter orange.May ↑ stimulatory effects when taken with ephedra and green tea.
Oral (Adults) Heart disease prevention—1–4 cups daily; Headache/mental performance—1–5 cups daily. One cup of black tea contains approximately 50 mg caffeine. A maximum of 8 cups/day has been suggested.

Availability

Tea leaves: OTC

Nursing implications

Nursing assessment

  • Assess BP and heart rate periodically in patients at risk for cardiovascular side effects.
  • Lab Test Considerations: Monitor liver and kidney function tests and blood glucose, plasma homocysteine, and uric acid levels periodically in patients with who drink large amounts of black tea.

Potential Nursing Diagnoses

Acute pain (Indications)

Implementation

  • Drink tea as desired.

Patient/Family Teaching

  • Advise patient that chronic use of black tea may be habit-forming. Abrupt discontinuation may lead to withdrawal symptoms; decrease gradually.

Evaluation/Desired Outcomes

  • Increased mental alertness.
  • Increased urine output.
  • Decrease in headache pain.

black tea

Tea made from leaves that have been fermented before they are dried.
See also: tea
References in periodicals archive ?
Total taxes and duties on the import of black tea include 10 per cent customs duty, 17pc GST, three per cent value added tax and six per cent income tax making cumulative incident of taxes and duties to 36pc which encourages arrival of tea through illegal routes.
Probably the oldest black tea producer in Japan, 90 year old Japanese-Brazilian, Elizabeth Ume Shimada attended the festival for the third consecutive year.
It was also found that 16 per cent of people believe black tea has too much caffeine in it to drink in the afternoon, while a further 13 per cent believe it's not good for hydration.
My teacher said she tried Korean black tea and that it was amazing _ I had never tried it before," Yang recalled.
A recent study has found the remedy for flu -a sore throat, fever, cough and stuffy nose- in red wine, black tea, and blueberries, reports Independent.
Conclusion: The findings that the pretreatment with black tea and vitamin C can mitigate carbofuran induced toxicity lend evidence that supplementation with either black tea extract and/or vitamin C have a therapeutic potential in amelioration of oxidative stress in mammalian systems.
sinensis), green and white are unfermented, black tea is fermented, and oolong tea is semifermented.
Available in a traditional premium loose leaf black tea and a refreshing loose leaf herbal infusion built on red Rooibos.
In terms of specific foods, black tea was the only individual food associated with a reduction in risk.
In Japan, and East Asian and Southeast Asian countries, the consumption of ready-made green and black tea in cans, packs or bottles has increased remarkably in recent years.
5 million metric tons of desiccated tea that are produced annually is processed as black tea which is used by many countries.
Not only for sipping, brewed black tea also flavors certain curries and desserts--and is even used in hair and body treatments.