black tea

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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 ?
have found that theaflavins and thearubigins, another key class of black tea polyphenols, can suppress A431 (human epidermoid carcinoma) and A375 (human malignant melanoma) cell proliferation without adversely impacting normal human epidermal keratinocytes.
Black tea contains several polyphenols such as bisflavonols, theaflavins (TFs) and thearubigins (TRs), whereas oolong tea contains the small amount of catechins and theaflavins.
Estimation of the market value of Central African tea by theaflavins analysis.
Each capsule used in the study contained 75 milligrams of theaflavins, a quantity of theaflavins that is equivalent to the amount of theaflavins present in as much as 35 cups of green tea or seven cups of black tea.
Most cell culture studies have been conducted with pure polyphenols, including especially curcumin, resveratrol [114], genistein, chrysin, and EGCG [107], cyanidin-3-glucoside [112], and catechin, theaflavin, malvidin, cyanidin, and apigenin [96], though extracts, especially red wine [69,109], apple (peel) [111], blueberry [113], and grape [110], have also been studied.
An effective black tea extract standardized for theaflavin content can be used alone or in combination with other ingredients for synergistic absorption, such as collagen for joint health, resveratrol for heart health or choline of healthy brain function depending on the formulation's objective and application.
Several types of bioactive compounds are found in WT such as polyphenols, caffeine, theogallin, gallic acid, theaflavin, flavonol glycosides and catechins particularly epigallocathechins (EGC), epigallocat-echins gallate (EGCG), epicatchin gallate (ECG) and epicatchin gallate (ECG) (Hilal and Engelhardt, 2007; Rusak et al.
It now now includes, in Supplement Facts order: pantethine (200 mg), artichoke leaf extract (600 mg), theaflavin (300 mg), polymethoxylated flavonoids (300 mg), grape seed extract (100 mg), PomGuard (100 mg), alpha lipoic acid (100 mg) and sesamin lignan (12 mg).
30% Sulfur and tea liquor quality * Sulfur Rate Theaflavin Thearubigin Brightness Total Color (kg per ha) (%) (%) (%) (Score) 0 2.
For the oxidation stage of manufacture, training includes the monitoring and control of oxidation, the role played by time, temperature and oxygen on made tea quality, the effect of dhool moisture content, the use of theaflavin analysis as a quality marker and standard oxidation.