Taste Perception in 2-Month-Old Infants
Yes, 2-month-old infants can taste bitterness and have a well-developed sense of taste that includes aversion to bitter flavors, making them likely to reject bitter-tasting TB medications and syrups. 1
Infant Taste Development at 2 Months
Infants are born with remarkably sensitive taste perception—they actually have more taste buds (approximately 10,000) than adults, which are more widely distributed throughout the oral cavity. 2 This heightened sensitivity means that 2-month-old babies experience tastes more intensely than older children or adults.
Specific Taste Responses in Young Infants
Sweet taste: Infants show an innate preference for sweetness from birth, which is evolutionarily programmed to attract them to energy-rich foods like breast milk. 1, 3
Bitter taste: Aversions to bitterness appear from a very early age and are present at 2 months. 1 Bitter flavors are likely to significantly decrease palatability and cause rejection of medications. 1
Salty taste: At 2 months, saltiness may be aversive or neutral to infants, with adult patterns of salt preference not developing until approximately age 2. 1
Practical Implications for TB Medication Administration
The bitter taste of TB medications will be detected and likely rejected by 2-month-old infants, requiring specific formulation strategies. 1
According to European Respiratory Society/WHO/IUATLD guidelines, TB drugs for young infants can be administered via syrup formulations (for isoniazid and rifampin), which may help mask bitterness, or through crushed tablets mixed with appropriate vehicles. 4 However, the guidelines acknowledge that lack of specific pediatric drug formulations can cause delays and interruptions in treatment due to palatability issues. 4
Clinical Strategies
Syrup formulations are preferred when available for isoniazid (H) and rifampin (R) in infants, as these may be better tolerated than crushed tablets. 4
Crushing tablets may be necessary for some medications like pyrazinamide (Z), which can be administered through a nasogastric tube if oral rejection is severe. 4
Adding sweet substances to medications is almost certain to increase palatability given infants' innate sweet preference, though this must be balanced against medication stability and dosing accuracy. 1
Important Caveats
The heightened taste sensitivity in 2-month-old infants means they will experience bitter medications more intensely than adults, potentially leading to feeding difficulties and treatment adherence challenges. 2 Directly observed therapy (DOT) is essential in pediatric TB treatment to ensure medication administration despite taste-related rejection. 4
Salivary protein composition may also influence bitter taste acceptance in young infants, with significant individual variability observed even at 3 months of age. 5 This means some infants may tolerate bitter medications better than others due to biological factors beyond simple taste preference.