Camellia sinensis


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Related to Camellia sinensis: Camellia japonica

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.

green tea

(green tee) ,

Camellia sinensis

(trade name)

Classification

Therapeutic: central nervous system stimulants
Bladder, esophageal, ovarian and pancreatic cancer risk reduction, mental alertness, hypotension, cervical dysplasia associated with human papillomavirus infection, hyperlipidemia, weight loss, protection of the skin from sun damage, genital warts, dental caries, Parkinson's disease

Action

Caffeine in green tea stimulates the CNS and cardiovascular system through adenosine receptor blockade and phosphodiesterase inhibition.

Therapeutic effects

Improved cognitive performance and mental alertness.

Pharmacokinetics

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

Time/action profile

ROUTEONSETPEAKDURATION
POUnknownUnknownUnknown

Contraindications/Precautions

Contraindicated in: Allergy/hypersensitivity; Pregnancy and lactation (doses >200 mg/day due to caffeine content ).
Use Cautiously in: Patients with caffeine sensitivity. Long term use of doses >250 mg/day may produce tolerance, psychological dependence, tachyarrhythmias, and sleep disturbances; Iron deficiency anemia (may worsen); Diabetes (may impair glucose control); Cardiac conditions (may induce arrhythmias in sensitive individuals); Bleeding disorders.

Adverse Reactions/Side Effects

Cardiovascular

  • arrhythmia
  • tachycardia

Central nervous system

  • agitation
  • dizziness
  • excitement
  • insomnia
  • tremors

Gastrointestinal

  • nausea
  • vomiting
  • diarrhea
  • hepatotoxicity
  • abdominal pain

Fluid and Electrolyte

  • hypokalemia

Endocrinologic

  • hyperglycemia

Hematologic

  • prolonged bleeding time

Interactions

Green tea may ↓ effects of adenosine.↑ risk of bleeding with anticoagulants or antiplatelet agents.↑ effects of CNS stimulants.May impair glucose control from antidiabetic agents.abrupt withdrawal can ↑ lithium levels.May ↓ dipyridamole —induced vasodilation.verapamil can ↑ caffeine concentrations by 25%.additive effects with methylxanthines.↑ risk of adverse cardiovascular effects with bitter orange.↑ risk of hepatotoxicity with hepatotoxic herbs or supplements.↑ risk of seizures, hypertension or stroke with ephedra and creatine.
Oral (Adults) Range: 1–10 cups/day. One cup provides approximately 60 mg of caffeine.

Availability

Tea leaves:

Nursing implications

Nursing assessment

  • Monitor BP and heart rate periodically during therapy.
  • Lab Test Considerations: Monitor serum glucose, homocysteine and uric acid levels periodically during therapy.
    • Monitor liver and kidney function periodically during therapy.

Potential Nursing Diagnoses

Impaired memory (Indications)

Implementation

  • May be taken as tea or as an extract in capsules.

Patient/Family Teaching

  • Advise women who may be pregnant or who are breastfeeding to limit green tea due to the caffeine content.

Evaluation/Desired Outcomes

  • Improvement in memory.

Camellia sinensis,

n See green tea.
References in periodicals archive ?
In the present study we evaluated the anticataleptic efficacy of NR-ANX-C, a polyherbal formulation containing bioactives of Withania somnifera, Ocimum sanctum, Camellia sinensis, triphala and shilajit in haloperidol induced catalepsy in mice.
The results of this research are also in accordance with findings of Rezaiinodehi et al, [19] about allelopathic effects of aquatic extracts of Camellia sinensis leaves on germination and growth of Amaranthus retrofletus L.
Armed with this knowledge, we will try to modify the growth conditions of a small plantation of Camellia sinensis plants this summer to produce a 'super tea' rich in polyphenols and high in antibacterial activity.
Best of the Bunch Curvacious camelias EVERY time that you brew up a pot of tea, you are using the dried leaves of Camellia sinensis but, of course, the poor plant never gets a chance to flower because of the continuous harvesting of its leaves and shoot tips.
Black, green, white, and oolong tea all come from the leaves of the Camellia sinensis plant, which grows indigenously in China, Japan, India, and Thailand.
As I said before, white, green, and black teas all come from the same plant, Camellia sinensis.
Though marketed as tea, they don't contain any leaves from the camellia sinensis.
No matter where it grows, all tea comes from the Camellia sinensis plant, native to southeastern Asia.
Green tea is made from the unfermented leaves of the Camellia sinensis plant.
Herbal teas made from flowers, roots, berries and such are properly called tisanes, to distinguish them from teas which actually come from the tea plant, camellia sinensis.
True" teas--black, green and oolong--all come from the same plant, camellia sinensis, indigenous to China, Tibet and India.
White tea is tea made from new growth buds and young leaves of the plant Camellia sinensis that are picked shortly before the buds have fully opened.