Latera has only a chemistry/pharmacy:Farmacia "Giambra Gianluigi", Via I Maggio 8.
Consider that, due to the small size of the town, sometimes you won't find the medicine you're looking for. Consider to check it in bordering towns like Gradoli or Valentano, or better Acquapendente. If not, you'll have to wait the ordination.
There are not hospitals or clinics in Latera, usually population goes to Acquapendente or Montefiascone.
There's only a doctor in Latera, people will indicate you him.
contact
There's a post office in Latera's main street, but you won't find internet points or other forms of contact. An old but still working telephone box is situated at the entrance of the town.
respect
When you are in Latera, consider that is a small town with a lot of senior citizens. Catholic customs are a sensitive matter in small towns like Latera so avoid discussions, most of all with older people. Be polite with local people, and consider that offending one person would involve the dislike of one third of the population. A person in Latera is linked with at least half of the inhabitants for kin, relationship of friendship.
If you come in Latera for the first time and feel yourself a bit scowled by local people, don't worry. They are only trying to understand who are you and what are you looking for there. Knowing or helping someone will bring you an immediate esteem and friendship: after the first impact, lateresi are very friendly and opened to 'foreigners'.
talk
If not an italian speaker, talking in Latera will be almost surely a trouble for you. Consider to bring with you at least a phrasebook. Latera's people talk in laterese between them, a dialect formed by a combination of roman, northern latium, tuscanian and umbrian dialects; laterese is very similar to italian language to be precise, it's italian with some particoular expressions and slangs and is easily understood by every italian. Most of all can speak good italian of course, but consider that some older person will speak only in the local slang.
Forget to talk in english or other languages. It would be very hard to find someone who speaks english, because the young population is little and they are not used to interact with tourists or travellers. Maybe you'll be lucky, but don't trust on this evenience.