Feelshion 6% Caffeine 1% Retinol Eye Cream

For the treatment of fatigue or drowsiness, OTC doses typically range from 100 mg to 200 mg every 3 to 4 hours as needed. When used as an adjunct for headaches, Caffeine is often administered in doses of 65 mg to 130 mg in combination with other analgesics. For respiratory depression, Caffeine and Sodium Benzoate may be administered intramuscularly or intravenously in doses of 250 mg to 500 mg.

In neonates (apnea of prematurity), the standard loading dose of Caffeine Citrate is 20 mg/kg (equivalent to 10 mg/kg of Caffeine base) administered intravenously or orally. This is followed by a maintenance dose of 5 mg/kg to 10 mg/kg once daily. Use in children for other indications must be strictly supervised by a pediatrician.

Renal Impairment

While Caffeine is primarily metabolized by the liver, its metabolites are excreted renally. In patients with severe renal impairment, there is a risk of metabolite accumulation; however, specific dose adjustment guidelines are not standardized. Monitoring for toxicity is recommended.

Hepatic Impairment

Since CYP1A2 is the primary metabolic pathway, patients with hepatic cirrhosis or severe liver dysfunction may experience a significantly prolonged Caffeine half-life. Dose reductions or extended intervals may be necessary.

Elderly Patients

Elderly patients may be more sensitive to the stimulant effects of Caffeine. Lower initial doses and careful monitoring for cardiovascular side effects (such as arrhythmias) are advised.

Oral Caffeine can be taken with or without food. If gastrointestinal upset occurs, taking it with a meal or milk may help. For neonatal use, the oral solution should be measured carefully with a calibrated syringe. Store all forms at room temperature away from moisture and heat. Do not use Caffeine products late in the evening if you experience insomnia.

If a dose is missed, it should be taken as soon as remembered. If it is almost time for the next scheduled dose, skip the missed dose. Do not double the dose to catch up.

Signs of acute Caffeine overdose include tremors, agitation, palpitations, rapid breathing, vomiting, and in severe cases, seizures or cardiac arrhythmias. In the event of a suspected overdose, contact a poison control center or seek emergency medical attention immediately.

> Important: Follow your healthcare provider's dosing instructions. Do not adjust your dose without medical guidance.

Commonly reported side effects include insomnia (difficulty falling or staying asleep), restlessness, nervousness, and irritability. Patients may also experience gastrointestinal symptoms such as nausea, epigastric pain, or increased gastric acid secretion, which can feel like a burning sensation in the chest or stomach.

Less frequent reactions include tachycardia (rapid heart rate), palpitations, diuresis (increased urination), and fine muscle tremors (particularly in the hands). Some patients may report flushing or lightheadedness shortly after administration.

Rare but documented effects include tinnitus (ringing in the ears), visual disturbances (scotomas), and hyperesthesia (increased sensitivity to touch or sound).

> Warning: Stop taking Caffeine and call your doctor immediately if you experience any of these.

• Cardiac Arrhythmias: Irregular heart rhythms or severe tachycardia that may feel like a racing or skipping heart.
• Seizures: Involuntary muscle contractions or loss of consciousness, often associated with very high serum levels.
• Severe Anxiety or Panic: Intense feelings of dread, chest tightness, or hyperventilation.
• Necrotizing Enterocolitis (NEC): In neonates, symptoms include abdominal distension, bloody stools, or vomiting; this is a rare but critical risk in premature infants receiving Caffeine Citrate.

Prolonged use of high-dose Caffeine can lead to physical dependence and tolerance. Withdrawal symptoms, including severe headaches, fatigue, and depressed mood, typically occur within 12 to 24 hours after cessation. Long-term excessive intake may also exacerbate bone density loss in populations with low calcium intake.

There are currently no FDA black box warnings for Caffeine or Caffeine Citrate. However, clinicians are cautioned regarding its use in patients with underlying cardiovascular disease or seizure disorders.

Report any unusual symptoms to your healthcare provider.

Caffeine should be used with caution in individuals with a history of peptic ulcers, as it stimulates gastric acid secretion. It is also a potent cardiovascular stimulant and should be monitored in patients with hypertension or pre-existing cardiac conditions. Patients should be aware that many over-the-counter products and beverages contain caffeine, which can lead to cumulative toxicity.

No FDA black box warnings for Caffeine.

• Cardiovascular Risks: Caffeine can increase heart rate and blood pressure. It may trigger arrhythmias in susceptible individuals, particularly those with Wolff-Parkinson-White syndrome or symptomatic PVCs.
• Seizure Disorders: High doses of Caffeine may lower the seizure threshold. Patients with epilepsy should use Caffeine products only under strict medical supervision.
• Psychiatric Effects: Caffeine can exacerbate symptoms of anxiety, bipolar disorder, and panic disorder. High intake has been linked to caffeine-induced psychosis in rare cases.
• Allergic Reactions: Although rare, anaphylaxis or severe skin reactions (urticaria) can occur. Discontinue use if a rash or swelling develops.

For neonates treated for apnea of prematurity, serum Caffeine levels should be monitored to ensure they remain within the therapeutic range (typically 5–25 mcg/mL). In adults, routine lab tests are generally not required unless toxicity is suspected, in which case serum electrolytes and ECG monitoring may be indicated.

While Caffeine is intended to increase alertness, excessive doses can cause tremors or anxiety that may impair fine motor skills. Use caution until you know how the medication affects you.

Alcohol can slow the clearance of Caffeine from the body, potentially increasing its stimulant effects and side-profile. Conversely, Caffeine may mask the sedative effects of alcohol, leading to "wide-awake drunkenness," which increases the risk of injury.

Abrupt discontinuation after chronic use can result in a withdrawal syndrome characterized by headache, fatigue, and irritability. A gradual reduction in intake (tapering) is recommended for those consuming high daily amounts.

> Important: Discuss all your medical conditions with your healthcare provider before starting Caffeine.

There are few absolute contraindications; however, Caffeine should not be used with highly potent sympathomimetic amines (like certain high-dose stimulants) where the combination could lead to hypertensive crisis or fatal arrhythmias.

• Ciprofloxacin and Norfloxacin: These quinolone antibiotics inhibit CYP1A2, significantly increasing Caffeine levels and the risk of toxicity.
• Fluvoxamine: This SSRI is a potent inhibitor of Caffeine metabolism; co-administration can increase Caffeine plasma concentrations by several-fold.
• Theophylline: As Caffeine is a metabolite of theophylline and shares similar mechanisms, concurrent use can lead to additive toxicity and dangerous serum levels.

• Oral Contraceptives: Estrogens can inhibit the metabolism of Caffeine, prolonging its half-life and increasing its effects.
• Mexiletine: May decrease Caffeine clearance by roughly 50%.
• Cimetidine: This H2-blocker can reduce the clearance of Caffeine, leading to increased stimulant effects.

• Grapefruit Juice: May slightly delay the absorption and metabolism of Caffeine.
• Dietary Caffeine: Consumption of coffee, tea, or chocolate while taking medicinal Caffeine can lead to additive effects and overstimulation.

• Ephedra (Ma Huang): Combining Caffeine with ephedra or other stimulant herbs significantly increases the risk of adverse cardiovascular events, including stroke and myocardial infarction.
• Echinacea: Some studies suggest echinacea may increase the plasma concentration of Caffeine by inhibiting its metabolism.

Caffeine may cause falsely elevated results in tests for urinary catecholamines (VMA) and may interfere with pharmacological stress tests using dipyridamole or adenosine. Patients should avoid Caffeine for 24 hours prior to a cardiac stress test.

> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking.

• Hypersensitivity: Caffeine is strictly contraindicated in individuals with a known history of severe allergic reactions (anaphylaxis) to caffeine or any components of the formulation (e.g., sodium benzoate in certain injections).
• Active Peptic Ulcer Disease: Due to its ability to stimulate gastric acid secretion, it should not be used during acute flare-ups of peptic ulcers.

• Severe Cardiac Arrhythmias: Patients with uncontrolled tachyarrhythmias should avoid medicinal Caffeine.
• Recent Myocardial Infarction: Caution is required in the post-infarct period due to the potential for increased myocardial oxygen demand.
• Severe Anxiety Disorders: May worsen symptoms of pre-existing panic disorder or generalized anxiety.

Patients who are sensitive to other methylxanthines, such as theophylline or theobromine, may also exhibit sensitivity to Caffeine. There is no known cross-sensitivity with barbiturates or NSAIDs, though they are often co-formulated.

> Important: Your healthcare provider will evaluate your complete medical history before prescribing Caffeine.

Caffeine is classified as FDA Pregnancy Category C. It readily crosses the placenta. While moderate consumption (less than 200 mg/day) is generally considered safe by the American College of Obstetricians and Gynecologists (ACOG, 2020), high doses have been associated with an increased risk of low birth weight and potentially miscarriage. Clinical use during pregnancy should only occur if the benefits clearly outweigh the risks.

Caffeine is excreted into breast milk in small amounts (typically less than 1% of the maternal dose). While generally compatible with breastfeeding, excessive maternal intake can cause irritability and poor sleeping patterns in the nursing infant. The American Academy of Pediatrics (AAP) suggests monitoring the infant for jitteriness.

Caffeine Citrate is specifically FDA-approved for the treatment of apnea of prematurity in neonates. It is not generally recommended for use as a stimulant in children under 12 years of age due to the risk of affecting developing nervous systems and sleep patterns.

Older adults may experience a slower clearance of Caffeine. There is an increased risk of sleep disturbances and cardiovascular sensitivity (e.g., palpitations) in this population. Monitoring for CNS and cardiac effects is essential.

In patients with end-stage renal disease (ESRD), the half-life of Caffeine may be altered, and the accumulation of metabolites is possible. No specific dose adjustments are provided in labeling, but clinical monitoring is advised.

Caffeine clearance is significantly reduced in patients with hepatic impairment, such as cirrhosis or hepatitis. According to studies published in the Journal of Hepatology, the half-life can exceed 60 hours in patients with severe liver disease, necessitating significant dose reductions.

> Important: Special populations require individualized medical assessment.

Caffeine's primary mechanism is the competitive antagonism of adenosine receptors, particularly the A1 and A2A subtypes. Adenosine normally acts as a CNS depressant; by blocking these receptors, Caffeine increases the release of excitatory neurotransmitters like dopamine and glutamate. Furthermore, Caffeine acts as a competitive inhibitor of the enzyme phosphodiesterase (PDE). By inhibiting PDE, Caffeine prevents the breakdown of cyclic AMP (cAMP), leading to prolonged effects of catecholamines and relaxation of bronchial smooth muscle.

The onset of action for oral Caffeine is approximately 15 to 45 minutes, with peak effects occurring around 1 hour. The duration of effect typically lasts 3 to 5 hours in adults. In the respiratory system, Caffeine stimulates the respiratory center in the medulla, increases minute ventilation, and improves diaphragmatic contractility.

| Parameter | Value |

|---|---|

| Bioavailability | 99% |

| Protein Binding | 25% - 36% |

| Half-life | 3 - 7 hours (Adults); 65 - 100 hours (Neonates) |

| Tmax | 0.5 - 2 hours |

| Metabolism | Hepatic (CYP1A2) |

| Excretion | Renal (1% - 5% unchanged) |

• Molecular Formula: C8H10N4O2
• Molecular Weight: 194.19 g/mol
• Solubility: Sparingly soluble in water; freely soluble in boiling water.
• Structure: 1,3,7-trimethylxanthine.

Caffeine is a methylxanthine derivative. It is classified as a Central Nervous System Stimulant [EPC] and a Respiratory Stimulant. It is chemically related to theophylline and theobromine.